How to get around being classified as a “raffle”?

I’m looking for a creative way to have a “raffle”.. but not?

For one of my business classes we are having a group competition- and we have to create a halloween event for the college- while the other groups are just putting a ‘report’ (marketing plan etc) together for their event- my group decided we would one-up-it and actually implement and hold our event on campus. However- we were given short notice of the project and upon research online and with advisors at the college- we cannot have a raffle unless we apply for a license with the state (and it takes 30 days to get approved) and since the assignment is due next week- that isn’t going to happen =) Our goal was to have a raffle ($1 per ticket) and use the raffle like a 50/50 and give away a $500 prize etc.. we were also getting local businesses to donate gift cards and products for us to raffle off. (we’ve already gotten some of the items from the businesses) Or idea was that almost anyone could find $1 to buy a ticket and with 30,000 students attending our college- we thought we would make a nice profit on the event also- besides giving away the cash. We also figured $500 was enough of an incentive to buy a $1 raffle ticket.. ( we didnt think 20- $20 prizes was enough to justify investing $1 into something for..)

So we have been brainstorming for a week now and are at a total road block. Does anyone have any suggestions or creative ways we could get around it being classified as a “raffle”..??? Or another event idea? (one group at school already holds a costume party/dance on halloween night).. we want our event to be during the week during the day next week… thanks in advance!