We actually have a forum for "shoestring meals" for those of us who are on a budget.
http://www.3fatchicks.com/forum/shoestring-meals-235/
I'm sorry that your premade meals get eaten before you have a chance.
How are you all eating right now? Do you ever sit together for meals? What does your family enjoy eating? Is there any way that the four adults can share the cooking?
Stores like Aldi, PriceRite, and Asian grocery stores can be a good place to start. Beans and eggs are really good sources of cheap protein, and so are canned fish (tuna and sardines). These stores usually have inexpensive produce as well as a variety of frozen produce.