Here's an example, I'm thinking about a family I used to know. They cooked a lot of pasta with meat sauce - easy, quick, feeds a lot, makes for easy leftovers. So keep the same pasta, switch to a non-meat marinara - same price so far. Instead of the ground beef, add in two cans of chickpeas. So same cooking time, still feeds a lot, same cooking skill, but the chickpeas are cheaper than the beef, so you come out ahead. It really is that easy.