For a start, I would like to say thank you for your work and what you are doing is wonderful.
However, I would like to add a few suggestions and wishes.
1. If the buyer chooses another method of payment, when buying a product, after the buyer completes the contact form - the seller does not...
I'm not sure if this would be possible on a market setup, but if possible it could be interesting to let people take card payments through stripe.
I guess each users that wished to do this would have to set up an account with Stripe themselves.
I was thinking it might be interesting to have a "gift card" system. Where users can buy an item or set aside a sum of money to spend in the marketplace. It could also be used by admin as a reward, for example for winning competitions.
XenForo > 1.4.x
XenForo Resource Manager > 1.1.x
Paypal Premier or Business account (for paypal payments)
RM Makertplace allows you and/or your users to sell resources from the resource manager, like in a marketplace !
Supports three types of products :