Paying $500 for a 0% chance to win; that doesn't sound like the best deal to me. You can get a lot more value from a regular hackathon that you can actually get some attention and feedback from and that isn't going to charge you a crazy amount of money. I don't understand how you can justify the competition when your app wasn't even viewed.

Edit: Apparently the ticket price was $100 and then reimbursed. That makes it better, but I would still argue you get more benefit from a standard hackathon.