I don't know how this will pan out. Higher prices on NIB pins seems to be raising the price of everything right now. ($3k for a good used pin doesn't seem so bad compared to $8k for something new.) Perhaps we will reach a saturation point if a lot of desirable new machines are available. On the other hand, that might simply serve to increase the popularity of the hobby, expanding the base and increasing demand for somewhat cheaper used pins.
All I am really sure of is that I will enjoy what I have and not count on my little collection to increase in value.