CNBC Make It spoke with shopping and retail experts to determine what are the best bargains at Costco beyond food. Here are 10 practical, useful items on which, they say, you can save big.
"If you don't mind not having designer frames, you'll save a lot more money if you get your prescription glasses at Costco, " Ramirez says. That goes for contacts as well.
Charlene Haugsven, founder of MyFrugalAdventures.com, has firsthand experience with this. "Just a couple months ago, I ordered four boxes of contacts from my optometrist and it was $220 — and I would have to wait three weeks for them," she tells Make It.
"I wound up going to Costco and I got them the same day and it was $143 with a $25 rebate. I ended up saving over $100."
Like paper products, non-perishable baby items are a smart buy at Costco, Skirboll says. Because parents will end up purchasing diapers, wipes and other baby products in bulk anyway, it makes sense to take advantage of Costco's deals.
"Think about how much you're paying per diaper," Skirboll says. Costco's Kirkland brand offers 192 diapers for $29.99, compared to far fewer for the same price at other retailers.
Home items, such as toilet paper, paper towels or laundry detergent, are usually going to be much cheaper if you buy in bulk. And because they aren't perishable, if you have the storage space, it can be worth stocking up, whether you're buying 30 rolls of toilet paper or a 96-pack.
"A lot of people get scared at Costco, like 'Do I really need 100 rolls of toilet paper?'" Skirboll says. "Don't get caught up too much in the numbers. It's not all crazy."
Costco offers instant rebates on name-brand tires, including Michelin, BFGoodrich and Bridgestone, according to Skirboll.
And buying through Costco comes with added benefits, Skirboll says, including lifetime rotation and balancing, lifetime warranty replacements and free nitrogen tire inflation.
Costco teams up with major brands, including Alamo, Avis and Enterprise, to offer reduced rates on rental cars. The savings can be significant: "in the double digits," depending on when and where you book, says Sara Skirboll, shopping expert at RetailMeNot.
Another perk of making travel plans through Costco is that you get access to on-call travel representatives who are able to answer any questions you might have. "You have someone you can call and talk to about what you're looking to do instead of having to do it all yourself," Skirboll says.
Because you're buying in bulk, over-the-counter medicine tends to be around 40 percent cheaper at Costco, Ramirez says.
However, if you're shopping on behalf of a furry friend, you'll find better deals elsewhere. "When it comes to your pet, stick to sites that specialize in pet products," he adds.
"Costco almost always will have a deal on gift cards," Ramirez says.
The bulk retailer sells discounted certificates for popular restaurants and events, including Peet's Coffee, Cold Stone, Regal Cinemas and Build-a-Bear Workshop.
It's worth checking out what your local store is has in stock. Ramirez has seen deals such as a four-pack of $15 Krispy Kreme gift cards for only $45 or a $100 credit for Cirque du Soleil for $80.
If you own an inkjet printer, you can save big by bringing the empty capsules to Costco's photo center to be replenished. Prices start at around $7 and "it's a lot cheaper if you get them refilled versus going out and buying a new cartridge," Tom's Guide deals editor Louis Ramirez tells Make It.
Just make sure that Costco accepts your brand and model ahead of time. Once you've done that, "they'll refill them for you while you shop and you'll get them within an hour or so," Ramirez says.
Both Skirboll and Ramirez recommend Costco for gas. Although prices fluctuate depending on location and economic climate, the retailer tends to offer lower prices than competitors in the same area.
"In some cases, with the gas savings alone the membership pays for itself," Skirboll says.
Skirboll and Ramirez agree: Costco doesn't always offer the lowest prices on electronics and appliances. But, Ramirez argues, depending on your lifestyle, the perks can sometimes outweigh the price difference.
"When you buy an electronic from Costco, you get free tech support from Costco for that product, " he says. "They will help you with anything from set up to troubleshooting to just random questions you may have about whatever device you bought."
Costco also extends the manufacturer's warranty on most items, giving you another year of coverage at no extra cost.
Additional reporting by Megan Leonhardt.
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