There are many plug-ins able to make vendors subscribe to a paid plan to sell on a multi vendor marketplace, but you can make them pay a fixed price only.
I'm looking for a customization of an existing plug in which lets me define a dynamic price, which will depend on the sales a vendor did in the previous month.
Basic plan: 0$ + 5% of their sales during the previous month
Gold plan: 10$ + 5% of their sales during the previous month
If vendor selected basic plan, and he sells items for 100$, at the ene of the month he'll pay 5$ to renew his membership, while if he selected gold plan and sold items for 500$, the renewal cost will be 10$+25$= 35$.