Are you looking for a solution to charge user for becoming seller or charge for approving seller's product.
If yes, Magento 2 Marketplace Seller Membership will be the best choice for you. With our marketplace seller memebership:
1. Admin can charge sellers for becoming a seller
2. Admin can charge sellers for adding limited number of products.
3. Admin can set seller's membership expire time also.
4. Admin can charge fixed or percent fee for enabling each product that they added from their account.
This is a plugin of Magento 2 Marketplace Extension. To use this module smoothly, you must install Magento 2 Marketplace Module first.