Okay, I'll admit that I'm spoiled, but there are certain things I'm not willing to cut corners on. If I want prosciutto, I want Proscuitto de Parma, or its equivalent. The knockoff supermarket version isn't worth it to me. If it's not in the budget that week, I don't have it. I have a wonderful bottle of 30 year old balsamic vinegar that I happily shelled out the big bucks for. It lasts for a long time and it does things to good that the supermarket stuff never will. And for me it's not just a money issue, I'm just as "line in the sand" with cheap stuff sometimes. If I want a Big Mac, I want a Big Mac. A Whopper, while quite tasty, is not a Big Mac and it just won't do when the spirit moves me.
What are the foods that you will not compromise on? Where it's the best (or your very favorite) and with feet dug in, it's your way or the highway.