Hello,
I think paid membership is an alternative solution to what we need, we exactly want to charge a fee for listing any product on our platform, we want to make money on any product they sell, a listing fee to to vendors is about 15% of the item price. So for example when an item sells for $100 the breakdown of fees looks like this:
1.Item price: $100
2.Net vendor earning: $85
3.Vendor fee: $15
I hope that I made myself clear, Thanks for your support.