I guess the only fault behind this would be the trust factor and how many complaint threads may be posted.
Would it be possible to add a (Buy/Sell/Trade) thread?
I just put all my computer supplies on ebay, because I'm moving into a dorm and can't take it all with me, and I'm sure a lot of people on here would have been interested in most of it.
I know this is a pretty hacked up version of vbulletin, but I saw a couple of implementations when looking for some for my board where you can link to your ebay sales in your profile and on your user info (under your mood or something) in the postbit. That way, JUPM wouldn't have to directly deal with buying and selling on the site, it would be completely through ebay.
Here's the idea:
I like the idea though..very nifty...and I have a few tech related items to be rid of and having a second place to sort of market it would be worthwhile...especially a security forum.