From my understanding, at least what I was told five years ago by my school's NCAA person, athletes are allowed to accept prize money up to the amount of the total cost of all gear worn (shoes, singlet, shorts, watch) and travel expenses (gas and tolls). While it doesn't add up to that much, it at least covers $200-$300 I would assume. Most athletes don't accept prize money if they are collegiate athletes, but I believe they can up to a certain extent. Correct me if I am wrong please.
You are allowed to accept actual and necessary expenses from a meet director, but cannot accept prize money. If a meet director wanted to pay for flights, hotel, gas, etc they could but you cannot accept prize money based on finish.