we pay tuition, books and rent. DS and DD pay for food and play money. DD makes about $400/mo, and it seems sufficient. DS has a car, thus has gas and insurance to pay as well. He earns about $800/mo, and this seems to cover all the above with plenty of wiggle room. We believe that working during school is part of the education process. The above said, we did give both an allowance during the first semester. DS was off campus, so his was about $300 for food and play money, DD was on campus which included cafeteria for food, so we gave her $100/month. This is all within the past two years, so probably still relevant.
Find Joy in the Journey...