 We want to make potato salad, but if you go to buy mayonnaise, it's going to cost you $6 a jar now. It just doesn't feel right to me. When NPR asked listeners this summer where inflation stings the most, grocery prices was one of their top concerns. Sure, those prices have inched up only about 1% in the last year or so, but food economist David Ortega of Michigan State University notes that's on top of a nearly 6% increase the previous year and a jump of almost 12% the year before that.