I don't think the seller realistically expects to get that price...although if some recently-obsessed collector with an "arab oil sheik" budget --or maybe a recent lottery winner on his initial buying spree-- sees the listing, he might. "It's a "buy it now" price, with the option for a potential buyer to offer/bid less. It SHOULD be set at a high level.
It doesn't hurt the seller to try, and in fact might help him to get a higher price than he would if he put a more realistic valuation on it. The effect of such an asking price is often to re-frame the potential buyer's perception of the item as something more costly, helping to push up the highest price he's willing to pay --even if his pushed-up maximum is still well below that asking price.
It's almost a variation on "auction fever", where someone gets caught up in the idea that other people are willing to pay more for something, and ends up paying more than he thought he would be willing to. (Okay, there is more "buy in" and other stuff going on with auction fever, but it's partly similar.)
The seller has made it clear that this item isn't just another receiver. By mentioning that only 300 are estimated to still exist, and then giving plausible reasons why this one might well be the best one of them all, he puts it in a (nearly) unique position, where someone who "only wants the best" will feel a compulsion to get it. If this is seen as your ONLY chance to get something you really want, how much will you pay? And if you know the guy puts such a high value on it, aren't you a little more likely to bid a little bit higher? Even if you aren't influenced by that BIN "valuation", you might fear that others would be, and so consider bidding a little more, to increase your chances of getting it.
He's unlikely to succeed at THAT high of a price level, but I give him credit for trying.