Hey, here's an idea, and I apologize if this has been brought up before, but how about a section where people can sell stuff online here? I don't mean anything like credit cards, or paypal, but for ex: a video game for sale: starting price, and after a few days, highest bidder, then continue the transaction through personal E-mail, how to pay/where to send/pick-up etc.
Some ground rules would be: Has to include a pic, and what condition it is in, start and end date for bids. For Safety, no personal meeting, no retail price, etc.
Cause I've got a lot of artwork/books/games/movies to sell, but no place to sell it.
what do you think?

Could just go in its respective boards, ie artwork in art, book in Lit, games in Game, etc. Or go in Random if you're in a hurry and want to get shit out fast, because I'm gonna be realistic with you, new boards are generally gonna be underused. It'll take a month or so for it to kick in, and even then, there aren't many people that will go in and talk about shit or whatever.

But in any case, if it works, it works. If it doesn't well, another board wasted but we'll get by.

The two main problems I can think of are these:
1) To implement all the things you stated would require a lot of coding UNLESS you're content with the board remaining in the same format as the others, meaning to find the highest bid you have to trawl through posts, and it's a bitch to work out when the auction ends.
2) How to deal with legislation: It is entirely possible that if that board is implemented, this site could be considered a commercial entity. That means Reltair has to start keeping records of every transaction/agreement and has to implement a whole load of stuff, along with the potential to pay taxes simply for that classification. You may think "But this site is in America, other country's laws don't apply here", but think again. There is actual (civil) precedent in Australian courts regarding whether websites hosted in other countries can be charged under Australian law if it can be proven that the site is regularly accessed by Australians - honestly, this has been used in a lot of slander/libel/whatever-you-Americans-call-it cases. Other countries may take this even further, and this could lead to any "agreement" having to factor in the extra overhead due to tariffs and the like.

A few problems are the ones that >>2 and >>3 pointed out. So instead of adding to the collection fairly extensive descriptions of problems, I'll suggest a few simple solutions.

Craigslist, Ebay, your local pawn shop, your neighbourhood/school, and even Facebook are usually fairly acceptable places to buy, sell, or advertise your things. There are other options as well, if anyone would prefer not to use the methods listed above.

To add to Umbra's post, if you're thinking of selling it to someone on here because you know some people who would be likely to want it you could just put your item up on whatever website you choose to use and then just give them the link in chat. I'd say make a post here, but (especially if you only have a couple people in mind) a whole thread seems a bit unnecessary.