I've actually always thought a non-refundable (meaning if you win, you have to pay even if you don't use the tickets, not that there's a $10 entry fee even if you don't win) $10 lottery, with all proceeds going to charity (or to, say, free tickets for the show for school kids, like Hamilton does) is the way to go. It prevents thousands of people all over the country from entering just for fun with no intention of using the tickets if they win, and allows the cost to remain low enough that you can raise some real money for charity while still making it a true lottery.