Actually, you may wish to pick up "The Four Hour Body" by Tim Ferriss… The dietary portion of that manual is very veggie-compatible, and the whole plan revolves around very simple, cheap, and easy to prepare meals. Black beans, especially, can be prepared in a LOT of interesting and delicious ways, are incredibly cheap in bulk, and basically keep forever dry.
Once you've got the basics down, it's also easy to start fiddling with ingredients to produce differentiated flavors, and keep things interesting…
Of course, this meal plan is also basically a fat loss diet plan, so if you're happy where you're at, make sure to either cheat a lot, only cook the recipes occasionally (1 of your dailies, perhaps?), or chuck the advice about cutting out soda and juice.
Mr. Luster's recipe is on my list for dinner tomorrow (any good meat-based substitutes for the Eggplant, Jonas? ), but it's definitely going to take a LOT longer to make than a "4HB" style meal… Which reminds me:
Whatever you cook yourself, unless you totally screw it up, is going to taste just a little bit better than the same thing made by someone else (for non-professionals, at least)… So if you're trying to keep things cheap, I'd focus more on that aspect at first – cooking ingredients that don't break the bank in a fashion you'll actually consume.
Then, work on cooking for tastiness once you've nailed cost-effective, and made regular meal prep a habitual part of your routine.