I think one needs to determine what constitutes a "proper" meal.
Since watching Forks over Knives, I have cut my meat intake back even further. I like a good bison fillet every now and then, but I really just don't eat a ton of meat.
To his point, if you and one other person like rice and beans, you can make a kick butt dish on the cheap that is going to give you plenty of nutrients, and for probably right around $4. Beans aren't expensive if you buy them raw and soak/cook them in house instead of buying the canned crap. The spices don't cost much, neither do raw onions and garlic, nor rice. I use shallots because they are very good for you, and garlic does a great job at fighting cancer is prepared properly. Toss in some diced bell pepper or jalapeno if you want, some tomato...whatever, and you have a pretty healthy meal on the cheapness.