Simmer lentils ($1 per lb) in veggie broth, spices and a bay leaf or roast chickpeas (less than $1 per can) with oil and spices for cheap and easy protein. Have a couple handfuls of mixed nuts and seeds everyday for healthy fat. Add cruciferous vegetables like broccoli and collar greens to meals when possible. You only need 0.4-0.5 grams of protein per lb of body weight, 0.6 if you work out all the time.