Here's another frugal food tip:
Streeeeeeettcccchhhh your ground meat. Most meals that call for ground meat can be stretched by adding lentils or rice to the meat.
For instance, I like to add brown rice to our taco meat. Lentils go great in sloppy joes. They both work in cheeseburgers (so does oatmeal.....my sister-in-law adds oatmeal to her cheeseburgers and they are so yummy!). All three of those ingredients could be added to meatballs. I think you get the drift.
If you want to do this, start slow. Just add a little bit of rice/lentils to the meat and then slowly add a bit more every time you make that meal. This is how I've done it and the carnivores in my family haven't complained!
How do you stretch your ground meat?