I personally have never ever, ever, seen anyone ever try to charge more than something should be worth on ebay, craigslist site. Seems as if one did see such an event and was not born yesterday you would presumably just laugh to yourself click out of it and move on.
By the way if he does sell it than it is worth that much, the value of something is worth what someone else is willing to pay for it; if he does not ever sell it than he is just wasting his own time.