Payment

I am thinking of investing in this plugin, but I have some questions. I would just like my members to sell to each other.

1. Is there some addon that will give my members the ability to have their own page or board where they can sell their items? They need to do it on the frontend. I dont want them to access the backend of my installation.

2. Do I need to give any of my credit information when its only my members who are selling and buying items. Can I just select the payment methods they can use?

3. I do have a WordPress Multiesite with Buddypress installed. I dont hope that will give problems?

http://wordpress.org/plugins/wpmarketplace/