There's been several threads on RGP recently discussing pinball pricing into the future. Prices do usually take a slight bump around the holidays, but the ones you quoted are fairly dramatic. I'd question whether or not a few of those sales were completed.
The pinball price explosion of the past 10 years is simply due to more and more people getting into pinball collecting, and all going after the full-feature machines of the 90's. The "A-list" price explosion (overall higher % increase) is due to so many people getting into collecting and immediately shaping their collections around the numerous "Top 10" lists, ie. everyone wanting the exact same few machines. The only good thing about the "follow the leader" mentality is that lots of pins get left in the Land of Lost Toys category and stay around $1000, because they're labeled "B-list" or "C-list." LOL, which is funny to me because that alone makes them undesirable to certain types of collectors, not because of the machines themselves or how they play, but simply because they're labled "B-list." So as expensive as the top tier stuff has become, you can still find really good pins in that $1K range. One benefit to the herd mentality.
From personal experience, I used to get crazy looks in the late 90's for (gasp) owning a brand new pinball machine in my home. It was considered pretty out there. But due to pinball dying on location, players who loved pinball had no choice but to own the machines, and routed machines were cheap 10 years ago, after all they didn't earn very well for ops anymore. So more and more collectors began building bigger and bigger collections from the cheap machines.
So then you had Craiglist connecting everyone, eBay as ready-made "price-check" for operators, guys going into pinball resale business, and the days of cheap machines were OVER, for good. Well, I mean like the days of talking to an operator (who nobody had ever even called) and going to buy his machines for $500 a piece...those days are over. I actually touched base with the very op I'm thinking of recently. He said he gets at least 2-3 calls per week from pinball collectors wanting to buy his non-existent broken machines, etc etc. LOL We had a good laugh about the 15-20 machines I bought from him back around 02-03. Those days will never return.
Like all hobbies which get hot, it will get cold again. There will be new plateaus. Prices will fluctuate. But with every living breathing human connected via the internet these days, the deals are gone for the most part, other than the odd CL-jump-in-your-car-drive-and-pray deals, the prices will remain fairly constant until a new pinnacle is reached in pinball. In other words, since you can't buy cheap machines anymore, you can't sell cheap machines anymore.
If JJP and Stern succeed in standardizing color lcd displays, and moving pinball back into locations, then you could see a drop in the older DMD stuff. Or at least, a dip in the super high-end stuff. Two or three years out. They will certainly not keep increasing at the rates they have been. AFM's will not be $12K in 5 years. MM will not be $20K. Just not going to happen. I think this moment in time right now is the absolute peak of DMD pin pricing. But that's under the assumption that a new pinnacle is coming soon. We'll see...
