Ok, reading through this thread again, it sounds like one reason that pricing is where it's at is that there is a lot of labor that goes into colorizing each game. There is also the point that mass producing items with relatively small market for each title (ex. Even if all were still in existence and every owner wanted one, there were only something like 7,000 demolition man pinball machines produced).
Here is what I don't understand though. If the color dmds are interchangeable and you just download the new ROM (for free, I'm assuming), then why wouldn't other manufacturers get into this business? It sounds like the work is in writing the code for each title, but that code is then just downloaded from the website.
Maybe I am missing something here, but this is interesting for sure.
Similar to whysnow, I would probably buy them for all of my (five) games if they ever dropped to a lower price point.