The "right buyer" thing refers to someone who is actively looking for a specific item in a specific condition at a specific time. Is there a market for an unrestored 1965 Mustang GT350 at $350k? Not really. But there is if the right TWO buyers are out there and are willing to bid it up.
http://www.autoblog.com/2012/01/21/barrett-jackson-2012-1965-shelby-gt350-barn-find-headed-to-a-ne/
(now speaking hypothetically)
Are you ALWAYS in the market for a specific pin? Let's say you go to an expo and happen to play a JP. You realize that the game plays great and you really got into it at the show and that now that you just sold one of your other pins two weeks ago, you've got room for a new-to-you title and decide JP is going to be next to add to your collection. Now, if you were a collector who can't work on your own machines for whatever reason, and don't even like the idea of opening one up to clean it and even replace rubbers as necessary, chances are you're going to look for one that is in fantastic condition that will also not need attention for a long time. That, along with the fact that you make $150k per year, and like to have nice things in good condition. Chances are, too, that you're going to pass on a JP that has a cabinet that is all dinged up and faded. No, you're going to wait for that one machine that comes along that is just a bit above the rest of them in quality. Once that stands out. It may take some time to find it, but you'll get it. Your discerning tastes require it.
Not only is the person above a "right buyer", but he wasn't even in the market a month ago. Games of a certain level take a right buyer at the right time.
Is the constant-lowering-of-price-unti-it-sells procedure warranted with a title like Kingpin? An original BBB? I know the old line "Something's only really worth what someone will pay", but sometimes you just hang on to something because you know it's worth what you're asking and the timing may not be right for a buyer to have stepped forward. I don't think that Kingpin that sold recently sold because the guy kept lowering his price until he found a taker.