Whole Foods has a few recipes and videos for how to make meals for 4 for under $15.  You could probably make it even cheaper if you bought the groceries someplace else (sorry, Whole Foods!)  Anyway, the recipes include Easy Tamale Casserole, Hearts of Palm and Avocado Salad with Three-Cheese Quiche, Italian Wedding Soup with Vegan Meatballs, Quick Scallops and Asparagus Risotto, Sausage and Artichoke Pizza.