When you think about shopping at Costco, bulk groceries and household supplies typically come to mind. You don't necessarily think about making a run to the warehouse club if you're looking to buy a designer watch or you need to re-up your stash of high-end skin cream. However, you could be missing out on huge savings. Costco stocks a limited selection of luxury goods at discounted prices both in-store and online.

We scoured the aisles at a Washington, D.C.-area Costco location and clicked around on Costco.com to see which luxury goods were available to members. Then, we compared the warehouse club's price against the manufacturer's suggested retail price for each item. Take a look at our surprising list of a dozen luxury items that are cheaper at Costco.

Are the Luxury Goods Sold at Costco Authentic?

But before you make a purchase, a word of caution. From fake Rolexes to knockoff Manolo Blahniks, counterfeit merchandise has long been the scourge of the luxury-goods market. Costco guarantees the authenticity of all the products its sells, a spokesperson confirmed, including luxury goods. The warehouse club also offers a "100% satisfaction guarantee," though the return policy on some items including high-end electronics and diamonds can vary. As with any retailer, it's important to understand the return policy before committing to a major purchase.

It's worth noting, as well, that the warehouse club isn't an authorized reseller for certain high-end products such as designer handbags and fragrances. However, don't be surprised if you see some of these luxury items on Costco shelves, as we did. As reported by Refinery29.com, so-called gray market goods can end up at Costco -- even though the manufacturer had no intention of having its merchandise sold at a discount at Costco -- because the warehouse club purchased the goods from a third party or perhaps direct from the factory.

Trae Bodge, a smart shopping expert at TrueTrae.com, recommends paying careful attention to the quality and condition of luxury goods sold at Costco, especially if Costco isn't an authorized reseller. Minor blemishes or subtle quality variations could explain why some of the items landed on the gray market rather than on the shelves of upscale boutiques.

Versace Aion Chronograph Men's Watch

If you go to Costco focused solely on restocking the kitchen pantry, you might've missed the enclosed glass case located near the entrance that's filled with designer watches. During a recent visit, we spotted timepieces from luxury brands such as Gucci, Omega and Salvatore Ferragamo. On the warehouse club's website, you might even be able to find more brands and product styles not available at your local club location. For example, we found a stainless steel Versace Aion Chronograph Men's Watch available for $649.99 (it's also available in a gold tone for an additional cost) on Costco.com. That same watch (in a bronze and gray color) sells for $1,495 on Versace.com. That's a 55% cost difference compared to the stainless steel version at the warehouse club.

Even at a deep discount, you're still paying a lot for your designer watch. Before you hand over your credit card to buy any luxury item, Retail Me Not's shopping and trends expert Sara Skirboll recommends checking the warranty. Is it the original manufacturer's warranty? If not, is the store warranty comparable? Also, does your credit card extend the warranty? You'll want to be sure your pricey purchase is protected.

Yves Saint Laurent Sac de Jour Souple 48-Hour Duffle Bag

This French fashion label has been lauded as one of the top luxury brands for decades. For those who can afford to buy Yves Saint Laurent products at full price, it's often second nature to shop at a high-end department store such as Bergdorf Goodman or at an actual YSL boutique. However, even the well-off can appreciate a good bargain on a designer find.

At Costco, members are privy to deep discounts on select fashion and beauty items from the iconic luxury brand. This includes the Sac de Jour Souple 48-Hour Duffle Bag in black leather, which retails for nearly $3,000 on YSL.com. We found the same handbag on Costco.com for about 25% less priced at $2,199.99. Keep in mind that Costco is not an authorized reseller of Yves Saint Laurent handbags, so it doesn't come with a manufacturer's warranty. It is protected under the warehouse club's guarantee. Should you decide to return it, you can only take it to Costco and not an actual YSL boutique or authorized reseller.

De'Longhi Magnifica XS Fully Automatic Espresso and Cappuccino Machine

If you like to indulge in a frothy mug of cappuccino or espresso at your local coffeehouse more often than you care to admit, it may be time to invest in your own machine. When buying an appliance that you'll be using frequently, think long and hard before going the cheapskate route. Opting for a lower-quality version that can't handle the constant wear-and-tear may end up costing you later if you have to replace it sooner than expected.

An appliance maker whose coffee, latte and cappuccino machines often appear on best product lists is De'Longhi, an international small appliance manufacturer. You can purchase their products at specialty and department stores such as Bloomingdales, Sur la Table and Williams-Sonoma. You can even find them on Costco.com, which is where we spotted their Magnifica XS Fully Automatic Espresso and Cappuccino Machine selling for $499.99. That's a steal compared to the $899.95 you'll spend if you buy direct from the manufacturer. You'll pay 45% more than at the warehouse club.

Apple Watch 5 Series With GPS

Loyal Apple customers know that the tech giant doesn't offer discounts through its e-commerce site or brick-and-mortar locations. If you want to score a deal on a coveted Apple item that isn't used, you'll typically have to wait to purchase it from an authorized reseller (think: Target or Best Buy) during a major holiday shopping weekend such as Black Friday. For example, during Target's 2018 holiday promotion the chain had Apple iPads and 3 series watches at discounted prices. Target even offered a free $150 store gift card with the purchase of an iPhone X.

Costco members currently on the hunt for an Apple Watch should log on to the warehouse club's e-commerce site. You'll find the tech giant's latest 5 Series watch (44mm case) with GPS on sale for $414.99. That's about $14 cheaper than what you'd pay on Apple.com, where it's available for $429. The watch isn't available in-store, so you'll have to purchase it online. You can pick it up at no extra cost in-store where you'll need to provide a valid photo ID or have it shipped to you directly for an additional $4.99.

Ray-Ban RB3558 Aviator Sunglasses

Ray-Ban sunglasses have been a longtime style staple in Hollywood having been worn by the likes of Will Smith and Tommy Lee Jones in the blockbuster "Men in Black" films to Tom Cruise in the cult classic "Risky Business." If you're a Costco member, you can channel your inner-film star for much less.

A pair of Ray Ban RB3558 Aviator Sunglasses sells for $93.99 (shipping and handling included) on Costco.com. That same sunglass style is priced at $168 on Ray-Ban.com -- a 45% cost difference. Keep in mind that these sunglasses may be available for a cheaper price at select store locations, but were not available at the Costco location we visited.

La Mer's "The Concentrate" Serum

The last place you might think to look for luxury skincare products is Costco. However, you're probably spending way too much if you only purchase your must-have products from specialty beauty or department stores. The warehouse club carries beauty counter staples from top-tier brands including Dior, Estee Lauder, SK-II and Shiseido. You can even purchase La Mer skincare products -- a favorite among some of the entertainment industry's most glamorous names including model and TV personality Chrissy Teigen and actress Kate Hudson -- for a fraction of the retail price.

We spotted a 1.7-ounce bottle of La Mer's "The Concentrate" facial serum selling for $399.99 (shipping and handling included) on Costco.com, although the warehouse club is not an authorized reseller. By comparison, the same size bottle of serum totals $500 on La Mer's e-commerce site. You'll spend an extra $100 buying this item direct from the manufacturer.

While LaMer products aren't sold in bulk quantities at Costco, you can purchase up to five individual bottles at one time. Skincare products -- especially, those containing SPF -- tend to have a short shelf life. Whether you buy one or five bottles of this serum, you'll want to make sure you're able to use it all up before it expires. Otherwise that deep discount ends up being money wasted.

Hartmann Excelsior 2-Piece Luggage Set

A quality luggage set is a must-have for frequent travelers. Costco offers several brands at varying price points. From the budget-friendly American Tourister line to the more upscale Bric's luggage collection, you can find a set that fits your needs and budget. We even found pieces from Hartmann, which regularly appears on "best luggage brand" round-ups in lifestyle publications such as Travel + Leisure and Good Housekeeping, on Costco.com.

You can buy Hartmann's Excelsior 2-Piece Hardside Spinner luggage set for a fraction of the manufacturer's suggested retail price. At Costco, you can score the set online only for $279.99 (standard UPS ground shipping included, except in Alaska, Hawaii and Puerto Rico). Meanwhile, you'll pay $429.99 for the same set on Hartmann's website.That's $150 more than at the warehouse club.

Retail Me Not's Skirboll reminds Costco shoppers to not be persuaded to make an unnecessary purchase just because you're paying an annual membership fee, which ranges from $60 to $120. If you come across a luxury item, but ultimately decide it's not worth the cost because you'll be able to get it elsewhere for a better price later or you're simply having an impulse shopping moment -- that's OK. When shelling out that much money, you want to be sure it's for something you'll get regular use from.

iRobot Roomba 985 Robot Vacuum

Spending your entire Saturday doing household chores can be a major time suck. From folding laundry to washing dishes, "working" on your day off can put a damper on the weekend. Vacuuming is often one of those dreaded tasks. It even ranks among the top five most-hated chores, according to Yelp.com's 2019 Modern Love and Household Responsibilities Survey, which examined household chores that put the most strain on couples.

This might explain why some consumers are willing to pay several hundred dollars for an iRobot Roomba 985 WiFi Connected Robot Vacuum, which retails for $729.72 on Amazon (where it has a 4 out of 5 star customer rating). It does most of the work for you, which makes it easier to simultaneously complete other tasks on your chore list. If you've had this robot vacuum on your wish list, but have been hesitant to spend that much, smart move. You can score a better deal at Costco where the vacuum sells for $599.99 -- about 20% less. You get to keep an extra $130 in your wallet.

Canon PowerShot SX530 Digital Camera

Finding a quality digital camera for the right price to capture your family's special moments can be time-consuming. There's a plethora of options, from the pricey digital single lens reflex or DSLR models to the simpler and less expensive point-and-shoot versions.

If you're not ready to commit to the regular maintenance and upkeep that's required when owning a DSLR camera, a point-and-shoot camera might be your best option. Costco has several including Canon's Powershot SX530 digital camera, which received a good rating (3.5 out of 5 stars) on PCMag.com. The online tech publication noted it's compact size, zoom quality, control layout and affordability as reasons why it's worth a look.

You can purchase the camera, which comes with a 16 GB SD card, on Costco.com or on Canon's e-commerce site for $249.99. What makes the warehouse club's offer the better bargain is that in addition to the camera and storage card, you'll also get a camera bag to neatly store the camera and its accessories all in one place. If you buy the camera direct from Canon, you'll have to pay an extra $23.99 for the camera bag, which bumps up the total cost by about 10%.

LG Signature 30 Cubic Feet Smart WiFi-Enabled InstaView Door-in-Door Refrigerator

When it comes to kitchen appliances, it doesn't get more luxe than owning a refrigerator that's euipped with smart technology. From being able to adjust the internal temperature using your smartphone to checking what's inside without actually having to open the fridge door, you're going to pay extra for the convenience. That's what you get with the LG Signature 30 Cubic Feet Smart WiFi-Enabled InstaView Door-in-Door refrigerator, which is a J.D. Power Award winner for kitchen appliance satisfaction. Some additional bells and whistles include LED lighting and a filtered air system, and it's compatible with Google Assistant.

You can purchase it at Costco for $3,699.99 (in-store and online). The price includes delivery, basic hook-up, removal of your old refrigerator and a two-year warranty. The manufacturer's suggested retail price is $4,399.99, but you can find the same model selling for $4,199.99 (only delivery is included) at Home Depot. That's $500 more than what you'd pay at Costco.

The warehouse club is a favorite among shoppers looking to get the best price on large appliances, according to a 2018 survey conducted by Consumer Reports. The survey also revealed that respondents shopped more for appliances at Costco.com versus in-store, because their e-commerce site offers a wider selection. Just be sure to compare the model numbers so you know you're buying the identical appliance.

Apple Airpod Wireless Headphones With Charging Case

Apple's Airpod wireless headphones are sure to be a popular gift request for the holiday shopping season. Before Black Friday hits and your only option is to camp out in front of your local Apple store or at an authorized reseller such as Best Buy, for hours before stores actually open, you can pick up a pair right now at Costco for less. At the warehouse club, members will pay $139.99 in-store for the wireless headphones and the accompanying charging case. On Apple.com, those same items sell for $159 -- $19 more than at Costco.

Bodge, the smart shopping expert, reminds shoppers that when buying certain luxury or high-end products that are hot-ticket items from the warehouse club, there will likely be a purchase limit. That's the case with the AirPod headphones. If you plan to buy them to give as gifts, you'll only be allowed to purchase two at one time and that applies online, too. Non-Costco members can also buy these headphones online for $144.99 with an additional 5% surcharge tacked onto the final total.

Designer Fragrances

With all of the luxury and high-end products available at Costco for cheaper prices, you may not want to set foot into a department store again. You can even buy designer fragrances and colognes at the warehouse club. During our in-store visit, we stumbled upon a bin full of such perfumes in varying sizes selling for $56.99 each. Some included a 4.25-ounce bottle of Marc Jacobs Daisy Eau So Fresh and a 2.5-ounce bottle of Chloe Love Story (which is also available online, but a bit more expensive at $69.99).

Costco's price point offers a huge savings compared to what you'd pay at a specialty beauty store such as Sephora. Here's what those fragrances in the same size bottles are selling for on the beauty retailer's website: The Chloe fragrance is priced at $132 -- 55% more. The Marc Jacobs perfume sells for $118 -- about 50% more.

Again, Costco is not an authorized reseller of these particular fragrances. There was even a disclaimer located on the bottom of the packaging that stated the following: "This product has been repackaged under the direction of Costco Wholesale Corporation, which is not related to the manufacturer."

It's worth noting that Costco.com offers a wider selection of fragrances versus what we saw in-store.

Andrea Browne Taylor is an editor at Kiplinger.