Rice in the 5 pound bag is pretty cheap [eggy rice knock off of a Japanese breakfast. I dope cooked rice with a splash of mirin, a splash of soy sauce, a tiny dab of hoisin sauce, mix well. Nuke gently til piping hot again, then crack an egg into it, stir in and eat.]
Assorted legumes by the 1 pound bag - split peas, great northern beans, lentils are my mainstays. Split pea soup using pork bones from some other meal, lentils with diced ham, great northern beans with chunks of bacon.
One mainstay is rischert/ricet. Cabbage soup is based on a very old family recipe from my Mom’s side. The original version has been found in a dig at the Halstatt Salt mines - white beans, barley, cabbage, greens, herbs, onions. My Mom’s version is based on the 17th century German version which her family brought over with them, over the centuries other veggies crept in based on migration of people and trade goods - black pepper, carrots, celery. She favored mustard greens, I favor spinach or bok choy. Meatwise, we have tried everything from squirrel, venison, horse, pig, cow, chicken, salmon [I really don’t recommend salmon] but I favor those fake country ribs that are boneless with a good veining of meat and fat. I rigged it to be a food pyramid in a pot for one person for all day eating - and cooked in the winter on a wood stove =)
4 cups shredded cabbage, 1 cup each barley and northern beans, 1 large onion, 1 bag baby spinach, 3 or 4 medium carrots, 3 or 4 ribs celery, Original was savory, mom preferred thyme, I prefer italian herb blend, black pepper and salt to taste, a pound of the country style boneless ribs.
A whole pot of this, 3 large meals or 3 moderate meals with snacks in between costs under $15US and is rich and filling, and warming if you have been outside in the winter shoveling the drive or other chores. I would serve it with homemade bread and a nice wine, but it really doesn’t need anything else - and would feed a family of 4 with bread and something like fruit or whatever for dessert.