I bought a set of high performance tires once that were listed as 89 dollars each, which I thought was incredibly low. I paid my price and as it turned out I had actually just gotten a 50% discount based off of a mistake in the system. I dont know for sure, but I think stores have to honor their advertised price on that item or else it is a matter of false advertising.
I can get Performance tires for about that price, just tire shops jack them up. If any of you ever need tires really cheap let me know. I've been ordering from a wholesale place for years, and I can refer you to them also.