Quoted from The_Director:

I think its some buyers that are the problem. Some people get their mind set on one pin and will pay any amount for it, and that to me is what hurts the market. I always have 5-6 pins I'd be very happy to own, some higher ranked than others, but try to wait for a deal on any of that batch. Or heck, not even a deal, just a fair price. With pricing the way it is now on a lot of games, you can't even rely on the Mr Pinball guide that game out a couple months ago because some turds are happily buying for $500-1000 more than book value.
Anyway, just feels a lot of people get into this hobby with no frame of reference and will pay any price. Maybe they have too much money they dont know what to do with or maybe it's something else, but it is frustrating with how it effects the market. I, personally, don't see these prices sticking around forever; like any market, buying high is not the way to go.
I try to do my part to buy reasonable and sell reasonable, and from what I have seen, most people that really love the game and not just the allure of the collecting aspect or the fly by night collectors do the same. We all love pinball and want everyone who wants to be involved to be involved. Just feels more fair to buy and sell as reasonable as possible and spread the love around, not try to make a fortune off every sell. The people I admire most in this hobby are the ones that help you find a good deal or sell you a good deal, knowing you will do the same for them one day when you can. I feel lucky in my area that most of the pinheads I know here are of that caliber, but it does seem pricing in general across the board is getting a bit out of control.