I have an owned license, but I'm not even gonna bother trying to sell it. Too many people now are looking for xF so I doubt I'll get anything worth worrying about for it. Not only that but mine is only for the vB3 license, which is arguably better than a vB4 but still it's old hat!! I'd rather hold on to mine, see what happens in a few years and if the market is with vB again, sell it then!!
Another place to keep an eye on is eBay. They seem to be having quite a few free listing days, so that could be an option!!