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Savvy Costco shoppers know how to make their membership cards pay them back and then some. But not everything is something you should buy at Costco -- or any wholesale club, for that matter.

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The country's favorite membership chain has been dishing out bulk-buying discounts to generations of shoppers. But how can you know what's a great deal and what you so pass on and look for elsewhere?

GOBankingRates asked the experts for advice on what to snag and what to skip both in stores and online. Here's a look at what you can't miss and what you'd be wise to avoid when shopping at Costco.

Between its discount kitchenware, alcohol, and diapers, stocking up at Costco can save you big time on anything you need to buy in bulk -- and even some smaller items, as well. Here's what to look for at the warehouse store.

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The famous Costco rotisserie is still located at the back of the store and is still just $4.99.

"One of our favorite Costco deals is the classic rotisserie chicken," said Collin Morgan, owner of Hip2Save.com. "Costco sells bigger chickens than most grocery stores for $2 to $3 less. These are a great bargain as-is for meals, but we like to buy them for recipes that call for shredded chicken." 

Morgan recommends Costco's store-brand diapers to get the best bang for your buck.

"Some Kirkland items are made by bigger name brands," she said. "Kirkland diapers are rumored to be made by the manufacturer of Huggies."

Batteries are another Kirkland Signature item that's worth buying.

"Kirkland batteries are actually made by Duracell, but the prices are much less than the name brands," Morgan said.

You don't have to pay an arm and a leg to eat organic, especially if you look for deals on organic foods at Costco. Their organic maple syrup is not only delicious, but it's cheap, selling for only 44 cents an ounce. That's a bargain compared to Walmart where their organic syrup sells for 80 cents an ounce.

"You'll almost always see a discounted rate for gift cards at Costco," said consumer analyst Julie Ramhold with DealNews.com. "It might not be a huge amount, but it's common to see things like two $25 See's gift cards for $39, or four $50 Texas de Brazil gift cards for only $154.99. Considering all you have to do is be a member, that's a hard discount to beat."

In addition to discounted restaurant gift cards, you can find theme and water park tickets, movie tickets, gym and weight management gift cards, and experience gift cards at discounted rates, she said.

Costco often has cheaper medication than chain pharmacies, especially for generics, Ramhold said.

"For instance, a 30-day supply of generic Zoloft can be as much as $12 at pharmacies like CVS," she said.

At Costco, a 90-day supply is closer to $9. That's roughly 11 cents per pill at Costco versus 24 cents per pill at Walgreens.

Not all Costco stores sell alcohol, but you can find great liquor deals at the ones that do, Ramhold said.

"For instance, many shoppers swear by Kirkland French Vodka -- in fact, rumors abound that it's actually Grey Goose, although that's been disproven," she said. "However, the reason people are so ready to believe it is because the vodka is just that good. Your mileage may vary on how much you'll save, but Costco's vodka is usually around $15 for 1.75 liters, and my local liquor store charges $60 for the same amount of Grey Goose."

"You can always find great deals on baby/toddler clothing and sleeper sets at Costco," said Rebecca Gramuglia, retail expert at TopCashback.com. "Whether you shop online or head to the store, Costco carries Carters, Nautica, Calvin Klein and many more."

Howard Schaffer, former general manager of Offers.com, recommended visiting Costco Wholesale for a wide range of kitchen items.

"You can score tables, chairs and tablecloths at Costco in a variety of sizes for a great price," he said. "Costco even offers kids tables and buffet tables if you're looking for something different."

For large crowds and potluck-style dinners, Schaffer noted the importance of having chafing dishes to keep food warm -- and advised purchasing them at Costco. It's also a great place to purchase glasses and dinnerware for hosting or everyday use.

"Costco sells disposable plates, napkins, cups -- including wine glasses -- and silverware in bulk for cheap," he said. "You can also stock up on other glassware or [serving ware] if disposable settings aren't your forte."

Perfectly packaged Costco gifts are great for any occasion.

"You can find large gourmet gift baskets and treat tins for great prices at Costco," Perez said.

Costco members receive 51% off every Shutterfly order, plus free shipping on orders over $49.

Kirkland Signature bacon received a nearly 4 out of 5-star rating on the Consumer Affairs review site. You can get four one-pound packages for $16.99.

Costco has both a great variety of eggs and great prices compared to many grocery stores, Business Insider reported. According to Costco's website, all of the chickens used in its egg production are cage-free.

Costco is famous for its food court's timeless $1.50 hot dog and soda deal -- and it was famous for its oversized $1 churros. Then, the deal got so hot that the churros disappeared. But now, according to Taste of Home, they've been spotted again at locations in California and places beyond. Although they're going for $1.50 now instead of $1, the churro deal is still too good to pass up if it comes to a Costco near you.

Costco's Kirkland Signature Organic Extra Virgin Olive Oil is professional-chef-approved. In the cookbook "Salt Fat Acid Heat," Samin Nosrat recommends this brand as one of the best-tasting olive oils you can get for your money, HuffPost reported.

Costco's store brand of creamy almond butter costs $7.99 for 27-ounces. Not only is Costco's almond butter cheaper than what you'd get at most stores, but it's healthier too, Cooking Light reported. The only ingredient in Costco's almond butter is roasted almonds, with no additional oils added.

Parmesan cheese has a longer shelf life than most other cheeses, so you can likely get away with buying it in bulk. Its per-unit cost is cheap compared to what you would get anywhere else, Business Insider reported.

Cereal has a long shelf-life, so you can enjoy the great deals Costco offers on both name-brand and Kirkland Signature cereals without having to worry about it going bad.

If you bake a lot, you know that nearly every recipe calls for vanilla extract. For the best price, GOBankingRates recommends buying it at Costco -- you can get two 8-ounce bottles for $32.99, paying only $2.06 per ounce. At Target, you'll find 2-ounce bottles of vanilla extract for $6.29 or $3.15 per ounce, over a dollar more than Costco's price.

Although best known for its supersized deals, Costco has a few items you'll want to consider skipping. You might find a better deal elsewhere, in some cases. In others, buying in bulk might just not be practical.

Not everything is a good deal when bought in bulk, and produce is a case in point.

"It's not that it isn't quality produce -- it can be really great -- but unless you're going to be able to eat it all fairly soon, you run the risk of it going bad," Ramhold said. "Unless you have concrete plans for those 5.5 pounds of pink lady apples, maybe skip the bulk buy and opt for your local grocery store instead to buy only what you need."

If you go to Costco searching for a specific book, you might not find it.

"Costco stores can have an OK selection, but you'll be able to find exactly what you want at Amazon," Ramhold said. "Even better, opt to support a local indie bookstore -- you tend to receive better customer service and you're supporting local, so it's a win-win."

"Costco has a variety of dried spices, but unless you use them frequently, you're probably better off buying smaller quantities elsewhere," Ramhold said. "Spices won't necessarily go 'bad,' but they will lose their potency over time. That huge thing of garlic powder might seem like a great purchase, but if it's hanging around a year later, odds are it won't taste nearly as good."

Canned goods are one item where the brand name really doesn't matter, so you won't necessarily get a better deal at Costco.

"Because Costco sells brand-name items, it's cheaper to buy canned goods at your local supermarket. Pay less by purchasing generic options rather than name-brand products," Gramuglia said. "More often than not, the difference is just the price tag, and generic products are just as tasty or reliable as notable, name brands."

"Before you're tempted to buy a year supply of detergent from Costco, be warned that it typically loses some its effectiveness after six months," Gramuglia said. "Instead, get a normal-sized container of your favorite detergent at Walmart for a great price."

Costco Wholesale often places DVDs and Blu-ray discs near the checkout lines in an attempt to lure customers into making impulse buys while waiting in line to pay. But these items aren't typically great bargains.

"You can find lower prices online or for pennies at your local thrift store," said Stephanie Nelson of The Coupon Mom who has conducted extensive research on wholesale clubs.

Costco Wholesale offers condiments in bulk sizes, but bigger isn't always better. After all, if you're not getting through your tub of mayonnaise before it expires, you're losing money.

"Unless you are entertaining, pay a lower cost overall by buying sale-priced condiments at the supermarket, with coupons that are frequently available on these items," Nelson said.

Every good party host knows the importance of having enough napkins to go around, but Costco deals on these items aren't always the best in town. Nelson said you can pick up sale-priced paper towels, toilet paper, napkins and tissues for less at supermarkets or big-box stores like Walmart and Target -- and that's before coupons.

Unless you have a large family that loves milk, chances are this purchase will go bad before you have a chance to finish it. The store also sells a wide variety of alt-milks, including almond, macadamia, oat, and coconut, all of which are likely too big for comfort.

Flour has a limited shelf life so it's not something you should buy in bulk, according to Eat This, Not That. If you do decide to go big, consult U.S. Flour or another organization that provides tutorials on how to safely store flour in bulk.

Soda will typically be cheaper at the grocery store, especially if you use coupons or take advantage of in-store promotions like two-for-one deals, according to Reader's Digest.

Nuts and seeds only last for a couple of months because they both contain high quantities of oil, which causes them to spoil, according to Eat This, Not That! Even if you get a good deal on these items at Costco, you might end up having to toss a lot away, which makes the deal not worth it.

Coffee tastes best when the beans are recently roasted, and that certainly won't be the case by the time you get to the bottom of the bulk beans you bought at Costco. Plus, coffee is relatively cheap even if you don't buy in bulk, so you're better off just buying it in a quantity that you can finish within a week or two.

Costco-sized tubs of hummus are too large for the typical household to get through before its expiration date.

Consumer Reports rated the Kirkland Signature Gel dishwasher detergent as one of the worst buys at Costco. Consumers said the product was ineffective at getting dishes, pots and pans clean.

Costco's Ara 13-inch 100% Visco Memory Foam mattress was also rated a product miss by Consumer Reports. It was rated low for back-sleepers and was only rated "mediocre" for providing stabilization.

Buying sunscreen in bulk might not be the best idea considering that sunscreen degrades and loses its efficacy over time. It might seem like a good deal, but if it goes bad before you use it, it can do more harm than good.

You can usually find better deals on rice at an ethnic market than at Costco. YouTuber Flo Lum reported that a 25-pound bag of Jasmine rice cost her about $40 at Costco (GOBankingRates found it for $21.99), but only $14 at a neighborhood Asian market, according to Money.

Look for deals on these products at chain drugstores, grocery stores and Target. When combined with coupons, you can usually get shampoo and conditioner for a better price than you would at Costco.

Beauty products have a shorter shelf-life than you might think. Liquid face makeup lasts six months, mascara lasts three months and skin care products last six months to a year at most, according to Good Housekeeping. Buying large containers or multipacks of beauty items will likely mean you won't get to use all of the product before it expires.

Don't assume that Costco will always have the best deals on electronics. Be sure to comparison shop for the same item at Best Buy, Walmart, etc. before hitting the check out.

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Gabrielle Olya and Andrew Lisa contributed to the reporting for this article.

Disclaimer: Prices are accurate as of March 6, 2023. Photos are for illustrative purposes only. As a result, some of the images may not reflect the products listed in this article.

This article originally appeared on GOBankingRates.com: The Best and Worst Deals at Costco