Even when I don't need to inexpensive yummy nutritious meals are my favs.

I second beans. Red beans and rice is filling and cheap. I also keep black beans on hand for refritos. The basic recipe is onions, cumin, garlic can of beans with some of the juice reserved as liquid. From there you can add jalapeño, cheese of your choice, rice, pineapple, whatever veggies you have. Serve with eggs or add salsa.

Also look around for how to cook beans and experiment. You can keep dry beans longer than can. Aduki beans don't require soaking. Really nutritious and fast to cook.

When I'm broke the first thing to go is bread. I might buy tortillas but rice serves me. Rice can also be stored for a long time.

Sprouts are easy to grow and very nutritious. The seeds also last for a long time. Theres a plastic sprout grower for about 20 usd or you can come up with one using and old canning type jar. You do not need an expensive setup.

Look for a blog called "poor girl eats well". She has recipes with an estimated cost.

I keep bacon around because you only need a small amount per serving and it's great for flavor. Cabbage roasted with bacon, olive oil, salt and pepper is really awesome winter food. You can't keep leftovers long though.

A basic veggie soup recipe is good to have on hand. Use whatever veggies are available.

Broth with frozen veggies. Not very filling but in a pinch or for a nutritious snack.

I am sooooo hungry now! I purposely didn't get specific on recipes in favor of more tips. Feel free to ask for specific on what appeals.