On the other hand, if everyone gets 5 up front, there is less incentive to buy additional tickets.
Also, not to be an ungrateful dick as above /ubbthreads/images/graemlins/smile.gif How about..
Admission charge gets you 1 ticket. For $5 you can buy an additional ticket. There is one series of drawings for the smaller prizes, where you can only win 1 prize. Then in the grand prize drawing, if you bought an extra ticket you are guaranteed to be in the running. If you didn't buy an extra ticket, you may not be in the running at that point if you alreayd won something.