No, I don't "seem" to be doing anything of the kind. The poor must. The rich choose. It's the key fact of the matter. As far as cheaper stores often missing from poorest neighborhoods: https://en.wikipedia.org/wiki/Food_desert Also competition between stores. (In wealthier neighborhoods I've seen people shopping in pairs, separate stores, comparing prices by phone.) Right next to the lower quality, lower priced brands - and holding down the prices of those brands. The rich choose. Incompetence is not a requirement of the calculation. If one is comparing the differences in the minimum cost of living for different economic classes, the differences in what they have to pay for and what they have to pay for it must be included, no? Rich people can even buy online, and have low priced stuff delivered to their doors. Poor people meet obstacles doing that - from credit cards and computer access to financial and package security - and these obstacles add cost.