Another option is to reset everyone each month or something.
For my uses, I give everyone $1000 to start with each month (after recording the top 10 for the previous month - hint Dartho to code in a monthly top earners feature

).
I also set a max bet limit of $500 so people can't blow it all in one go (another hint to Dartho so I don't have to keep hacking this in

) - search the old vbookie thread for "max limit" and you'll find the necessary hack to do this.
Cheers,
Regs.