Back in the 60s when my father-in-law was in grad school he ate nothing but frozen peas, rice, and some god-awful part of the cow for 25 cents a day. It's probably a little more now but with fiscal restraint and bulk purchases you could probably eat for $50 a month; I use "eat" loosely to mean consuming nutrients. If you're a vegetarian you could probably make it rice and liquid egg...CostCo has a pretty good deal on liquid egg. Maybe someone on the internet sells powdered egg really cheap. Dried beans in bulk might be a good deal. The fruit/vegetable part of the meal will probably cost you the most.