It has been suggested before but to be honest, we'd rather not as any disputes etc could come back on us. We do have the Shopping board and will allow people to post the odd item for sale, particularly if the proceeds are going to charity or whatever but we don't really want this to be expanded further at the moment, sorry. If you do have things you want to sell, there's always Ebay and Freecycle (for items you want to give away)
