You are probably right. I can tell you that, in the Sainsbury's supermarket chain, prepared meat such as salt beef costs in the range of the most expensive kinds of non-kosher luxury prepared meat, namely bresaola (part-dried spiced beef) and Parma ham, namely more than two pounds per hundred gram. I don't know how that translates into American measures, but it's a lot, and I can't imagine a modestly off Jewish family paying that much on food without either having to live on a stringent diet, or going without a lot of other things.