Do you notice those Taco Bell commercials, where customers pay for their food with exactly 89 cents? I don't know where these commercials take place. According to Federation of Tax Administrators, there aren't many states that have no sales tax, and there are local sales taxes, too. As you can see at Wikipedia, many states exempt unprepared food from sales tax, but prepared restaurant food is often taxed.
How many places are there where a person can pay exactly 89 cents for an item listed on Taco Bell's menu for 89 cents? Not too many. I call you out, Taco Bell commercials, for being annoying.