We sell advance tickets through a form, sent out school wide. We ask that parents send the form back, with check/money in a ziploc bag. We return the tickets to them in the ziploc bag. I do ask them to send in even amounts, in lots of 10 ($2.00 for 10), to make counting easier. We fold the tickets into groups of ten, and count out how many we need, put them BACK in the ziploc bag, and send the to the teacher to send home with the students.
Our festival is in the fall, and I am planning a few changes. We normally give out prizes for every event, but will give out "hound dollars" this year, where they can purchase things through the prize hut (probably similar to what you do). This alleviates children receiving things they don't want. The hound dollars are used in the spring, so we will save them for use in the fall. Kids will receive a different amount, depending on how successful the game is. They will not receive anything with the inflatables, since they are such an expense to begin with.
We are also adding a new thing, a wristband ticket system, where people can purchase a wristband, and do all the games/inflatables all day, for the one charge. Probably about $8.00 presale, and $10.00 at the door. Concessions will be cash only. We will also hold a silent auction.
That's all I can think of for now. Oh yeah, we have three inflatables, one rock climbing wall, and around 10 games. We also have face painting, and sand art (a huge hit last year).
Best of luck!