The problem with this theory, IMO, is that to a company selling pinball machines, selling 1000 machines at $10K each is the same as selling 2000 machines at $5K each. However, to me, I see the second scenario as much better for pinball as a hobby. An influx of people in to the hobby is not the only reason for increasing prices, and maybe not even the biggest reason. People have more money to spend for a variety of reasons.

Right now, there is a strong and fairly numerous core group of collectors with ample cash or at least who can get ample cash whenever needed. But one's faith in the whole "economics 101" thing would blow up real quick if say, a handful of Saudi Billionaires decided to buy every Stern pin for the next 10 years to give away as door prizes. All it would take is a small group of people with more money and influence to start controlling inventory and price, and the whole middle strata of collectors would be wondering what the hell happened. In reality, this will likely never happen, but in theory it could. This is why I hate using the market to explain prices, as if the market is some benevolent force that can't be questioned.