Contest Theme "Payment Info on File"

I like to see some place or a few places to se t"Payment Info on File"as the theme people can come as they are but can only enter the contest if they have payment info on file.  I wonder if anyone would anyone give it a try before the alts of alts start crying not fair when all they do is just stand around enter a contest and leave when all is over and go on to the next one, without giving a tip to any of the staff.

This was just a thought that I thought I would put out there, I doubt it would happen but may get rid of some of the alts at some parties.