Also, it's very arguable that if you are sitting on a big expensive collection, in just one generations time, you are not going to see any monetary value pay you back what you have invested even, as values plummet as the last of that 'real' generation exits this mortal coil.
This is a very real possibility.
I'm not saying the scene will die, of course not, but it will evolve & the ones that take up the slack are from a digital age don't forget, that shiny plastic doesn't have the same appeal.
This will happen, 15 years max IMO.
While there will always be a market, not unlike old stamps or something, but this market will be a fraction of the size.
I know a very well known DJ we all know who agrees & thinking of getting rid of stuff just sat at home too, for these very reasons given his age & he has NEVER sold from his collection on the past.
The clock is ticking all the time.