H.M.
My 6 year old is a big veggie fanatic, so I send some sort of cut of veggies every day. Sometimes I include a little container of Ranch dressing too. I always send either fresh or prepackaged fruit/applesauce and a granola bar. We buy lunch size chips in bulk at Sam's. I open a bag of those and half it so that it lasts two days (half of a bag fits perfectly into snack size baggies). That way he is still getting the chips that he wants, but it's not more than he needs and I save a few cents too. :)
Also, I just read an article about interesting school lunches and we tried one out yesterday. Take a cinnamon flavored tortilla. Spread honey nut cream cheese over it and put in several slices of thinly sliced apples. Roll it up. The cream cheese will help it stick together. My son said it was great and more fun than his regular PB&J.