As a student, I can tell you right now that eating raw can be the cheapest or most expensive commitment you make. The key to keeping prices low is making meals as simple as possible and limiting those tempting pre-made raw cookies, flavored nuts, etc.
But as for not feeling great on the living foods diet, maybe you should go back and take baby steps to being 100% raw, or try to include more dense, high-energy foods (dates, bananas, nuts) throughout the day.
Either way, good luck to you and your family!
