No price posted, no PMs accepted, just make an offer - but a reasonable one...
It was easy to tell that your sale was not going to go well. This is not an on-line auction site, there are plenty of those elsewhere. If you want to sell something here, post an asking price and then your potential customers have something to work with. Several people asked you to do exactly that, but you chose to ignore the requests. Now you want to whine about it...
He should just have posted his Craigslist ad.