5 Costco items that are always worth buying—one $10 deal can 'easily feed a family of 4'

Costco is known for its low prices and loyal customers who are willing to spend at least $60 per year on a membership fee.

The wholesaler has some of the lowest prices around—especially its Kirkland Signature store brand products—but the size of the discount varies depending on what you buy. Plus, bulk-size perishable items can spoil or go stale before you're finished with them, making them less of a bargain.

With that in mind, CNBC Make It asked Julie Ramhold, a consumer analyst at DealNews.com, for some of the best Costco items worth buying.

Note that prices can vary between Costco stores, and that in-store prices tend to be cheaper than what's found online. You also need an annual membership to shop at Costco stores, which can factor into how much you save.

Costco offers very low prices on bacon if you buy it in bulk. Ramhold recommends the four-pound package of Kirkland Signature Premium Sliced Bacon, which can be found for $15.29, she says. That works out to $3.82 per pound, whereas prices at other stores tend to be closer to $6, says Ramhold.

With bacon, you can always store it in a freezer to stretch out its use over four months.

"Costco's prices are so good, there's just no beating them, and I can vouch for the quality, which is excellent, too," says Ramhold.

While Costco's Kirkland Signature Super Premium Vanilla Ice Cream isn't the absolute cheapest ice cream you can buy, it is "premium-level delicious" and can be found for roughly $8 per gallon, depending on where you shop, says Ramhold.

That's a good price compared to other premium brands of ice cream of the same size, such as Blue Bell, which can be found for $8.32 at Walmart stores in select locations.

"We keep it on hand to have with pie, brownies or even to mix into coffee for a special weekend treat," says Ramhold. "It has become a household staple—even when it's cold outside."

There is a variety of honey products at Costco, but Ramhold's personal favorite is the five-pound bottle of Kirkland Signature Wildflower Honey, which can be found for $17.99 online, although in-store prices tend to be cheaper, she says.

That works out to about 23 cents per ounce, which is "far better" than name-brand retailers that sell honey for as high as 50 cents per ounce, says Ramhold.

Buying honey in bulk can offer good value, too, since it can last a long time—up to 12 months, if not more.

Since you'll likely have driven to Costco, you might as well get a full tank of gas while you're there. Costco's gas prices tend to be cheaper than what you'll find at nearby gas stations.

As of Thursday, a gallon of regular gas at a New York Costco costs $3.09, compared with about $3.40 at nearby gas stations, per Gas Buddy data. For 20 gallons, that works out to just more than $6 in savings, which can add up over time.

Just be aware that Costco gas stations are popular, so long lines are common, especially on weekends or just before and after work hours on weekdays.

Costco's best-known deal is the absurdly cheap $1.50 hot dog and 20-ounce drink combo. 

However, its 18-inch large pizza can be found for $9.95 in store food courts. At that size, "you can easily feed a family of four," says Ramhold. Considering that individual fast-food meals are typically more than $10, that's about as cheap a meal as you can find.