Another thing that might help is to check on vegetarian recipe sites as beans are a good, cheap vegetarian source of protein. For example, here's the Vegetarian Times website's bean link: http://www.vegetariantimes.com/search/?search=beans&page=1&tableid=260&start=1
If you want something about a specific sort of bean, just enter the bean type in the search engine and it'll bring up only those recipes. Some of them are incredibly inexpensive like this: http://www.vegetariantimes.com/recipe/7187
Do you have a crockpot? If you do, that makes it really easy to cook dried beans -- you soak them all night and then put them in the crockpot in the morning. Cans of beans are pretty inexpensive, but dried are even more so.