Hopefully you have a crock pot. If not, a big pot on super low on the stove.
Dry edible beans are cheap. Dry barley, cheap! Dry slit peas, cheap! Brown, non instant rice, Cheap! Lentils, high in protein, cheap!
You may not be able as I am, but if another option, go hunting. Deer, goose, duck, lean meat! Go fishing! Lots of options.
Garden! Even in an apartment in the city, with no visible land, you can grow veggies, with a bit of trial and error, container garden.
Heck, I live in cold, crappy western Nebraska, and I have, in a pot a blooming green pepper plant, I have not babied this!
Eggs are awesome! So versatile.
Save up, get a food dehydrator (like $39 at wal mart) and in the peak of garden season, take all the free stuff you can get and dry it and save for later.
Dried fruit, veggies, herbs and spices!
If all else fails, where I live we have more jobs than people! And more industry moving in! If you are willing to work, come on out!
