Don't make these 5 costly mistakes at Trader Joe's

Exterior of Trader Joe's located in Edgewater, New Jersey. 
Megan Leonhardt | CNBC 

Trader Joe's started out as a small chain of convenience stores, but today it's one of America's favorite grocery destinations. In fact, in a recent Consumer Reports survey of over 75,000 shoppers, it was the highest-ranked national chain.

The chain, which has almost 500 locations nationwide, offers lots of bargains as well as quirky products you don't see anywhere else, which helps it stand out from the crowd, says John Karolefski, grocery store analyst and editor of Grocery Stories. Not to mention the friendly employees, hand-designed signs, and of course, the free samples.

Still, not everything sold there is going to be a great deal for you. Here are five mistakes to avoid next time you're shopping at Trader Joe's to maximize your savings.

1. You buy fresh, not frozen meat

Trader Joe's fresh meat can be a bit more expensive than competitors, so make sure to price check before you buy.
Megan Leonhardt | CNBC

In general, meat at Trader Joe's can be a bit more expensive than competitors. But in many cases, the California-based grocery chain offers higher-quality options, such as organic and grass-fed meats. Yet other grocery chains have increased their organic and sustainable offerings in recent years, so before you add that package of chicken to your cart, you may want to at least check the prices elsewhere — even if it's only in the nearby freezer section.

"It's so much more expensive, and honestly, I think the packages don't have a ton in them," says frugal shopping expert Lauren Greutman of Trader Joe's fresh meat. Especially when it comes to chicken, she adds.

If you're a regular Trader Joe's shopper, it's often a better deal to stick with their frozen meat. For example, the chain sells fresh organic chicken breasts for $5.99 a pound, according to prices verified by CNBC Make It in Northern New Jersey. The all-natural variety of chicken breasts sell for $4.49 per pound. But a 40-ounce bag of frozen chicken breasts is $6.99, which makes it just 17 cents per ounce as opposed to 28 cents per ounce for the fresh, all-natural chicken.

There are exceptions. Currently, Trader Joe's sells both fresh and frozen organic, grass-fed, 85% lean ground beef for $5.99 per pound, for example.

If you're looking for less expensive fresh organic meat, Aldi may be your best bet. The grocery chain sells its Simple Nature brand of organic chicken breasts for $5.79 per pound, according to national average prices the chain provided to CNBC Make It in April. Meanwhile, Aldi's Simply Nature organic grass fed ground beef sells for $5.29 per pound.

2. You buy all your dairy at Trader Joe's

Trader Joe's offers a wide range of milk, but you may find better prices at other grocery chains.
Megan Leonhardt | CNBC

Some of Trader Joe's dairy products are a bargain, such as their specialty cheeses. For example, the chain's Unexpected Cheddar Cheese, which regularly earns praise, is only $3.99 for a 7-ounce package. The cheese was even voted a favorite in the chain's annual customer choice survey.

But make sure you're comparing prices on other dairy items. Aldi sells its 16-ounce package of Countryside Creamery stick butter for $1.99, a dollar cheaper than Trader Joe's similar product. While Trader Joe's sells name-brand butter, Kerrygold Irish Butter, for $3.19, the same product is cheaper at both Target and Walmart. Target also has better prices on products like sour cream and half and half, according to CNBC Make It's analysis.

Another item to price check: Trader Joe's organic milk. The chain sells its organic variety of 2% milk for $3.49 for a half gallon, which can be a bit more than you would pay elsewhere, depending on the location. In Northern New Jersey, for example, Walmart sells a half gallon of Great Value Organic 2% milk for $3.12, while Aldi and Target both sell their organic store brand varieties for $3.29.

It's worth noting that Aldi U.S. and Trader Joe's are independently operated companies with distinct but once-related corporate parents.

3. You don't use coupons

Trader Joe's does sell some name-brand products, such as Kerrygold Irish butter.
Megan Leonhardt | CNBC

A vast majority of Trader Joe's products are sold under its private label store brand, which means you definitely can't use coupons on these items.

But savvy shoppers know that not all the goods sold at Trader Joe's are private label. Each store typically has a limited selection of name brand items on its shelves and the chain does accept manufacturer coupons for these products.

For example, on a recent trip to Trader Joe's in New Jersey, the location had not only Kerrygold butter, but also TruMoo chocolate milk. Store employees have noted that some locations carry Amy's and Stonyfield products.

Some locations stock FAGE yogurt for 10 cents less than the local grocery store, the Krazy Coupon Lady site finds. So if you have a coupon, you can score big deals.

4. You buy all your produce at Trader Joe's

A view of the produce section at Trader Joe's in New Jersey.
Megan Leonhardt | CNBC

Bananas may be a good deal at Trader Joe's — they're just 19 cents each — but you may want to skip buying many of your other fresh fruits and veggies here. Numerous blogs, websites and even employees have weighed in on Trader Joe's produce and the overwhelming opinion is that it's generally disappointing compared to many of the chain's other high-quality products.

Produce may not be cheaper anyway. For example, Trader Joe's sells a 6-ounce bag of organic baby spinach for $2.29, which is about 38 cents per ounce. Whole Foods sells organic baby spinach under its 365 Everyday Value for $4.99 for a 1-pound container, which is about 31 cents per ounce.

5. You buy a whole package of a new snack without trying it

Trader Joe's routinely adds new products to its line-up.
Megan Leonhardt | CNBC

Trader Joe's is always rolling out new and interesting products. Some are destined to become your new go-to favorites —  but others, not so much.

But did you know that you can ask an associate to try any of the products in-store? You can! And this can save you money. That's because those specialty items, in particular, can end up costing you, according to frugal shopping expert Lauren Greutman. "They do such a great job marketing and packaging and making everything look pretty, so we spend a lot of extra money," she says.

The next time you're debating a new product, ask to try a sample before you buy the whole package. Your wallet will thank you.

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Grocery expert: Here's the 'secret to saving money' on food
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