Soups and salads are both very healthy, cheap, easy to make, come in wondrous varieties, and are quick to make.
For non-nutritious, cheap, and easy, that will fill the tummy in a hurry:
1 can potted meat, 2 tbs. pickle relish, 1 tbs. Miracle Whip, two slices of whole wheat bread. Copmbine the first three ingrediants and place between the bread slices.
But seriously, sandwiches can be nutritious, cheap, and quick, with readily available ingrediants, as can be various wraps. Use shredded Romain or Savoy lettuce instead of iceburgh though as it is far more nutritious. You can include things like garlic, onion, sliced roasts of any kind of meat you like, various cheeses, tomato, olive oil, peppers sweet or hot, and healthy breads. Use condiments like mustard and well-flavored extra-virgin olive oil, balsamic vinegar, dill pickles, etc.
Another very healthy, deliscious, and cheap meal, in-a-glass, are tofu/fruit smoothies. These pack a nutritious wallop, are quick and cheap to make, and taste amazingly good. Just take one brick of silken tofu, a banana, one or two pears, or apples, water, maybe a few fresh blueberries, or strawberries, or pitted cherries, kiwi, etc. and enough water to make it all blend smoothly. I add Splenda to mine, but you can rely on the natural sweetness of the fruit.
These smothies are also great with combinations of citrus, such as, but not limited to - lemon, lime, oranges, grapefuits, blood oranges, tangerines, clementines, etc.
I also throw freshly peeled, washed, and sliced carrot into my smoothies. You can also add spices such as nutmeg, cinamon, mace, allspice, etc.
Hope this helps.