Buy the inexpensive whole chicken. Roast in a clay cooker or other efficient container with a few cut onions, herbs and pepper...not too much salt.
Bake some bread and a squash at the same time, and a pilaf on the bottom shelf. There you have it: 4 or 5 ready, inexpensive meals (just add salad or cooked green/yellow veg). You save by shopping less, paying less, and cooking less. Similar thinking can be used with tofu, pork, beef, salmon, and other protein sources.