A fundraiser at a convention included a 50/50 drawing - where winner keeps half the money raised. Instead of a flat fee for tickets, they were sold 4 tickets for $5 or an arm's length for $10. Really encouraged many purchases of the $10. A lot of money raised.
Few other tips for successful 50/50:
1. Need immediate gratification. More sales if drawing is that same day/night;
2. Have double-tickets and announce winner by ticket numbers (must be present to win). If add details like requiring names and phone number it slows down sales;
3. Have many ticket salespeople, not just a few. If they're just sitting at a desk selling tickets, it's not as effective as a lot of people walking to each table selling them too. But do need to sell at registration desk too.