I would avoid the brown rice, even if soaked/fermented/sprouted. From what I understand, the phytates in both brown rice and oats are largely unaffected by soaking/sprouting. You may want to look into buckwheat, which is not a grain at all, and maybe stick to the white rice as a filler (useless for nutrition, but not actively evil in smallish amounts). Just don't sprout the buckwheat (look up photofagy if you want to know why).
I believe that there are several types of beans that aren't improved much by soaking/sprouting/fermenting either- black beans are one of those. I'd stick to lentils for most of the legume consumption. Plus you can sprout them in under 24 hours.
Home made bone broth is a protein sparer- it makes the protein that you consume go farther, so that you need less. Very useful if you're on a budget, as you can get cheap or free bones, and simmer for 1-3 days in a crock pot. Just add vinegar to the bones and water before you turn it on (you can also cook the meat in the crock pot with water, use that broth, then throw the bones back in and add more water and vinegar to get more broth). It also aids digestion, so if you use the broth to cook your grains, or drink it when you're eating the grains, it'll help you to digest them better (ditto for the legumes/pulses).
As others have said, you're basically asking about a Real Food/Nourishing Traditions WOE. NT has TONS of recipes, though not all are for the budget (like salmon roe dip), but are nutrient dense, and prepared for best digestion.
As for just budgeting- I'd be all over eggs, coconut milk, and bacon. They can all be a little pricey, but they take less to fill you up and will keep you going longer. Also cheap- organ meats, canned sardines, and the bone broth that I mentioned. Also, check around you for stores that sell bent and dent cans. My mother often picks up high quality sardines, canned mackerel, and the like for $0.45 and less per can. Some of these places even have excellent freezer sections, and even produce for on the cheap. Also, you can simmer fish heads/bones for about 2 hours to get a highly nutritious broth.