I was a moderator of couple of racing sites and buy/sell forum was one of the forums I moderated and I think if this site is to have a buy/sell forum, I believe some of the following rules should apply in order to protect the buyers/sellers and the site:
1: No non-sponsor commercial sales. If you are a vendor wishing to promote a product, please contact a forum administrator about forum sponsorship.
This is to prevent vendors from selling products without the owner's concent and any illegal mass sales.
2: You MUST post a price on all sales, posts that do not list prices will be DELETED!
This is prevent arguments between sellers and buyers. You want to eliminate any shady deals.
3: Links to Ebay ads are OK with EBAY in the subject line, but please no bidding in the thread.
4: No bidding allowed in threads. You can negotiate price and make offers, but please do not list items as B/O or similar.
Bidding will cause arguments and seller will pit buyers against eachother to get more than what the product's actual worth.
4: You must own what you sell. No posting for friends or relatives.
This is to eliminate selling of any stolen goods on this site.
5. Just because you reply first, that does not guarantee you a sale. The item could be listed on several sites, in different forums, in the newspaper, on ebay, etc... Seller reserves all rights to sell or decline a sale to whomever he wishes.
Also should remind the members that the site is not responsible of any transactions between buyers and sellers and anyone who is deemed to be a bad seller (recieved the money but fail to send the products or shipment of damage goods without prior announcement) will be banned from the site, at least banned from buy/sell forums.