bean, vegetables, fruits, nuts...might as well live to enjoy your savings

I recently read an article about why the simple yet fulfilling dish of beans and rice is so universal. It's served literally all over the world, with each region putting their own spin on it through seasoning variations. For literally pennies a serving, it's worth exploring the options.
Also, eggs, although high in cholesterol, are an excellent source of protein and, when prepared healthfully, are a very cheap source of nutrition.

Beans, lentils, tuna, frozen veggies, bananas...

I'm surprised nobody mentioned whole wheat pasta. It's very filling and because of its low-glycemic index, it takes a while to digest and doesn't leave you feeling hungry again in two hours.

I'm with Liz - eggs are the perfect food. The whole cholesterol thing - saturated and trans fats contribute more to blood cholesterol than actually eating dietary cholesterol. Plus they are cheap and (did you know?) can be left out of the refrigerator for at least a week before you even have to consider that they might go bad.

lasagna/pizza...make your own or buy the stouffers kind from the grocery.