I have been eating more legumes for protein. As well as lentils, beans, and tofu, I found a chickpea pasta I like a lot (Bonza, but cooked for only 4 minutes). It's expensive for pasta, but not as a protein source. I didn't do this to save money--I like legumes and and I like how easy they are to store and cook. However, saving money over other protein sources is a nice added benefit.