You can find some great deals at the dollar store -- that is, if you shop at a store where everything costs just $1. Despite their names, Dollar General and Family Dollar do not charge a dollar or less for everything. However, Dollar Tree and 99 Cents Only do.

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Even if you're paying a buck for some items at these stores, though, you're paying too much. That's because there are other stores where you can find them for less.

Click through to find out when the $1 price isn't the best deal.

Toothpaste Costs More Per Ounce

There are plenty of best buys at Dollar Tree, but toothpaste is not among them. Although the $1 price tag might look like a deal, you'll pay more per ounce than at Walmart.

For example, a 2.9-ounce tube of Crest regular paste costs $1.25 at Dollar Tree, which means you're paying 34 cents per ounce. A pack of three 6-ounce tubes of Colgate costs $4.97 at Walmart, but that's about 27.6 cents per ounce.

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Soap Isn't a Steal

You'll pay less per ounce for soap at Walmart than at Dollar Tree. For example, a pack of two 3.2-ounce Irish Spring soap bars costs 19.5 cents per ounce at Dollar Tree. But a 12-pack of 3.7-ounce bars that costs $7.97 at Walmart works out to be just 18 cents per ounce.

If you want to stock up on soap, you'll pay $11.48 for a 20-pack of Irish Spring at Sam's Club versus 18 two-bar packs at Dollar Tree priced at $22.50. Plus, the soap bars in the Sam's Club 20-pack are 4 ounces each compared with 3.2-ounce bars at Dollar Tree.

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Pain Relievers Are Pricier

Ease your pain for less by stocking up on acetaminophen or ibuprofen at Target or Costco rather than Dollar Tree. A bottle with 40 caplets of 500 mg acetaminophen costs 3 cents per caplet at Dollar Tree. However, the $7.99 bottle of 500 caplets at Target is just 1.6 cents per caplet. And a bottle of 1,000 caplets that sells for $12.43 at Costco is less than 1.2 cents per caplet.

You'd have to buy 25 40-caplet bottles of ibuprofen for $31.25 at Dollar Tree to get as many caplets in Costco's 1,000-caplet bottle that costs just $12.43.

You Won't Save on Cereal

You'll get a better deal on cereal at the supermarket and Walmart than at the dollar store. A 3.5-ounce pouch of Honey Nut Cheerios that sells for $1.25 at Dollar Tree is less bang for your buck than an 15.4-ounce box that sells for $3.49 at Kroger.

If your kids (or you) love Cap'n Crunch cereal, you'll save 8 cents per ounce by buying a 40-ounce bag for $5.98 at Walmart instead of a 5.5-ounce box for $1.25 at Dollar Tree.

Salt Costs Twice as Much

Jars of spices for $1.25 are a good deal at the dollar store, but you're better off buying salt at the supermarket. A 26-ounce canister of iodized salt costs half as much at Kroger as it does at Dollar Tree -- 65 cents versus $1.25.

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Canned Vegetable Prices Can't Compete

If you're paying $1.25 for a can of vegetables at the dollar store, you're overspending. For example, you can get a 15.25-ounce can of corn for 89 cents at Kroger and for just 50 cents at Walmart. You'll pay less and get more buying elsewhere because the Dollar Tree can of corn is only 14.75 ounces.

Canned Tuna Is Cheaper Elsewhere

Canned tuna is an inexpensive food that's good for you, but buying it at the dollar store will cost you more than at Walmart.

At Dollar Tree, you can get a 5-ounce can of StarKist Chunk Light Tuna for $1.25. But you'll pay about $1.09 per 5-ounce can if you buy a four-pack of them for $4.34 at Walmart.

Rice Isn't Really a Deal

Long-grain white rice is a good pantry staple, but it's not a best deal at the dollar store. You'll pay 75 cents per pound for a 32-ounce bag of long-grain white rice at Dollar Tree. Kroger's 5-pound bag that sells for $3.69 is just 74 cents per pound.

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Brand-Name Cleaning Products Aren't the Best Values

You'll pay less per ounce for brand-name cleaning products at Walmart than at the dollar store. A 28-ounce container of Ajax costs 88 cents at Walmart versus $1.25 at Dollar Tree.

Lysol multi-surface cleaner costs 5 cents less per ounce at Walmart for a 48-ounce bottle that costs $3.47 than for a 10.75-ounce bottle at Dollar Tree for $1.25.

Brand-Name Laundry Detergent Isn't a Bargain

Paying $1.25 for a bottle of laundry detergent might seem like a bargain, but you only get 10 ounces of Tide Clean and Fresh at Dollar Tree. That means you're paying about 13 cents per ounce.

You'll pay just 6 cents per ounce for a 138-ounce bottle of Tide Clean and Fresh that costs $8.94 at Walmart. And a bottle that size will last a lot longer, saving you trips to the store to buy more.

Disclaimer: All prices were sourced from the retailers' websites.

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This article originally appeared on GOBankingRates.com: 10 Ways the Dollar Store Actually Could Be Costing You More