Meatloaf - use pork rind as filler
Cheaper cuts of chicken (thighs, drumsticks) - bake w/ lots of seasonings - leave that skin on!
I agree w/ the quiche ideas - great way to use up leftover veggies and grated cheeses.
"Fajitas" are another favourite cheap meal - buy inexpensive beef or chicken - since I'm on maintenance I can eat a few tortillas - otherwise just the meat w/ fried onions and green peppers mixed w/ melted grated cheese and sour cream is really good. Fajita spice can be a bit carby for those on induction.
Cabbage lasagna! Steam cabbage leaves and use instead of noodles. Fry ground meat w/ onions, garlic and green pepper (sometimes I add zucchini and mushrooms too) - throw in a can of tomato sauce and tomato paste. In another bowl mix cottage cheese (or ricotta) w/ grated mozzarella. Layer cabbage, meat and cheeses in a casserole dish. Bake and serve.
Another tasty thing to do with cabbage is slice it thinly and fry in lots of butter until it starts to brown. Great w/ pork or sausages.

To be honest - I find I can eat fairly inexpensively now that I don't buy as much prepackaged foods. If you didn't in the past anyway, then I can see how the grocery bill would go up.

Lisa