40's cars haven't tanked. Nice ones are still expensive and the top collector cars are over six figures. That's a bad analogy to pick, since they *can* still be used the same way as a new car since all the controls are the same and they operate within the same laws as new cars.
Jukebox is better, since even getting 45s is a chore. They're completely obsolete. However, there are definitely people who like the look and feel aspect of them - I know I do, and if I had the space I might even have one. Some of them are gorgeous just as works of art.
If you want a good analogy, look at EMs. Have they gone up in price? Some have - the top tier games sure, but you can still find wedgeheads under $500. I mean, they used to be $50 or $100, but adjust for inflation and they've basically stayed stagnant.
Why? There is no demand for EMs.
So that tells me at some point there will be no demand for SS or DMD games. But there would need to be some replacement for DMD games and I'm not really seeing it. Not even JJP is really making radical changes that would obsolete DMD games.
Until that happens I expect pins will maintain their values, but probably not at crazy levels.