We have a friend who lived on macaroni and cheese throughout college, and developed a lifelong addiction to the stuff. At 25 cents a box, tough to beat. For Christmas one year as a joke, we gave her a big carton of the EXPENSIVE macaroni and cheese. Movin' on up! But seriously, I lived on peanut butter and jam on whole grain bread for much of my college years and the ones right after. I could still live easily on beans, rice, potatoes, garlic, tomatoes, etc. if I had to. Easy and cheap to grow (except for the rice) and they store well.