On the flip side, it's no surprise that New York City leads the list of places where toothpaste costs the most, topping out at an average of $4.49 a tube in Manhattan, CouponFollow finds.

If you're looking for the cheapest toothpaste, on average, you'll need to head for the border. Harlingen, Texas — just a few miles from Mexico — sells toothpaste for less than $1.50, on average, according to a recent report from coupon index site CouponFollow . Harlingen has been named one of the cheapest places to live in the U.S. and PayScale reports that the cost of living there is 21 percent lower than the national average.

Where you live determines so much of your daily life — even down to the price of your toothpaste. New data shows that certain parts of the country are paying roughly $3 per tube more than other cities, a shocking mark up on a household staple.

Sadly for New Yorkers, Manhattan and Brooklyn both rank among the most expensive markets in the U.S. for all groceries, with prices across the board around 140 percent higher than the median. Seattle, Oakland and San Francisco round out the top five priciest cities for groceries.

CouponFellow's analysis is based off the average prices of common groceries during the first three quarters of 2017 from the the Council for Community and Economic Research. The report limited the pool of cities to the continental U.S. , excluding Hawaii, Alaska, and Puerto Rico, as the cost of delivering many of the goods to those remote locations skewed the data.

"It seems there is a correlation between large metro areas and increased prices across a variety of products," Marc Mezzacca, founder of CouponFollow, tells CNBC Make It. He adds that there are exceptions, however, particularly when a product is a vegetable or pantry staple produced in that state.

Seattle's status as one of the most expensive cities came as a surprise to the data team at CouponFollow. But Mezzacca says that prices in this Washington metro have been on the rise for several years.

"Large price gaps occur even in the same state," Mezzacca says, adding these can be "quite shocking" at times. For those who do live in a major city, he says it may be worth it to drive out of the metro area to do big shopping hauls.

Another option may be to follow Mark Cuban's advice and, when you find a sale online, buy a two years supply of toothpaste all at once.

Don't miss: I spent 1 month cooking all of my meals—here are my 7 best tips for saving on groceries

Like this story? Like CNBC Make It on Facebook!