Never used the site, as it doesn't have the protections that I would like. Consider selling directly here on the forum where you can get all of the profits. Use a trusted escrow and little can go wrong. I know the convenience of sites like this but if it's hurting your profit that much then it just isn't worth it.
what kind of protections did you have in mind? like against chargebacks and stuff? I would sell here but I think it would be frowned upon. I might just gather some trustworthy people and form a small group on slack or discord, and deal with everything directly, so there are no fees at all (besides network fees).