I'm sorry, but I think that your theory makes no sense what so ever. Maybe 3-4 years ago Stern was the only show in town. Now, there are at least 5 companies making pinball machines, and that number will most likely increase. The technology is getting better by the day, and the market for pinball machines, and associated products is growing by the day as well. With a growing market and the number of existing and very collectable machines decreasing daily; the price has nowhere to go but up.
Although highly unlikely, due to the growing number of new machine buyers; the price for new games could possibly decrease slightly or stay the same, but the older machines and machines that are no longer being produced have a much better chance of going up in value.
I strongly believe that games like Wizard of OZ will see dramatic increases in value once they are no longer being produced.
The hobby is in an upswing. The market is growing and there is absolutely no reason for it not to continue to grow at an even more accelerated rate than it has been. Pinball bars and arcades are popping up everywhere. Tournaments and leagues are getting more and more popular. Pinball shows are growing in size and becoming more popular year after year .
You sound like someone that just wants to pay less for his games. It is just not going to happen any time soon, and their is a much better chance that the value of the top 100 games or so increase in value substantially over the next 10 years than there is for them to decrease in value at all.
Unlike the stock market, which is controlled and fixed by the hedge fund managers and the extremely wealthy .... The pinball marketplace is a great supply and demand example, and all indicators are pointing upwards.

Manny

You can not compare the decline of value attributed to arcade games to pinball machines . Arcade games are worth almost nothing excluding the very few classic games because the home video games have surpassed them in graphics and everything else . You will never be able to truly compare a VP to a real pinball machine. Pinball machines are truly one of the last mechanical products still being produced.
The demand for older games will continue to increase as more and more people get involved with the hobby. There is also no way to replace a machine that is destroyed accidentally without taking it out of the finite supply of games that are no longer being produced. The more people that get into the hobby, the higher the prices will go for the games no longer available new. There will never be a crash as there was in the arcade market. Up until Jersey Jack started making machines, it had been a very long time since anyone but Stern was building new pinball machines . Now there are half a dozen if not more companies that make new pinball machines . Demand is growing, the number of hobbyists is growing, and the amount of flippers is growing; all of which will lead to higher prices moving forward.
There is no way that you will see a crash in the pinball market within the next 10 years, if ever. If I had more money to play with, I would absolutely buy up every pinball machine deal that i could find and hold them as long as possible. Pinball collecting is one of the few hobbies where you have a real chance to gain value over time. I am speaking about buying older DMD machines and the classics, not brand new in the box machines, which will generally take quite a while to increase in value . There are always the exceptions, but most new games pretty much lose at most 10-15% of their value within the first 3 years. That is not bad at all...
Manny