The main demographic in pinball is 40-60 years old and are the ones that can afford and buy NIB games. I personally do not know anyone under 30 that has bought even a single NIB game. Unfortunately that is the generation that will be replacing the main generation currently buying and therefore the answer to the op's question is that Pinball is doing well now and for the near future but will almost certainly collapse from its current state when old farts like myself are replaced by the millennials. If you treat pinball as a hobby then enjoy your games but if you are looking at pinball as a long term investment, forget about it.