I found this video via Upworthy. It offers a look at how consumer prices might really be impacted if companies like Walmart paid its employees enough that they don't have to be on food stamps.
It's also worth noting that many of those on food stamps are hard workers; in fact, many of them work 50 or 60 hours a week, with multiple jobs, and still can't make ends meet.
In truth, the rest of us are subsidizing many of the workers at companies with low wages because of welfare programs and what-not. There's plenty of corporate welfare in this country, and that doesn't even count the social services provided to the employees of companies that pay terribly. And it might not even be good business. Costco pays a living wage, offers good benefits, and has a CEO that doesn't think that he needs millions upon millions of dollars a year in compensation, and Costco is doing just fine, and offering great deals to consumers.
So, really, prices won't go out of control if companies pay enough to keep their workers of food stamps.