The diminishing pool of vintage watch parts reminds me of a story that I heard many years ago. There is a well known vintage aircraft collector who, for many years, was buying up whatever V-12 engines/parts he could find to support his "fleet". One day he and a friend of mine who worked for him were standing in his warehouse looking at the floor to ceiling racks filled with pickled engines. The collector turned to my friend and said that it was a good thing he was able to save all of these engines and keep them from "the hoarders". My friends predictable response was "we ARE the hoarders".
I guess it really depends on where you are in your obsession, and what you need that others have.