Here's what I would do-
Eggs for breakfasts along with homemade bread (use eggs), buy flour and yeast.
Leftovers for all lunches.
1. Mexican (use corn tortillas, hamburger, cheddar, salsa, sour cream)
2. Pizza Margarita (use diced tomatoes, mozzarella, and the flour and yeast mentioned before)
3. Chicken, rice, and artichoke bake (use chicken and artichokes, along with a little of the sour cream and some spices for a sauce)
4-7 can use new ingredients based on what's fresh. All you've purchased so far is the flour and yeast, so just under $10 per dinner/lunch set isn't hard to pull off at all. You could probably even do it for half that and still eat reasonably well.