Maybe you are further down the line, but maybe something that builds security for the PP Bazar Team, and maybe benefits the community better is a subscription?
A flat fee, per month (keeping your book keeping simple) with different price points based on features the sellers get (home page featuring). I have paid on average of €100 to PP Bazar fees over the last 18 months, but say it was €50. You wouldn't have the issue of most of your sales occurring outside the bazar. So maybe you would end up better off.
However it may discourage newcomers to the bazar, limit machine choice, or not make enough to cover overheads.