Not to randomly jump in the conversation, but I was actually thinking about this last night, and was actually wondering if its the opposite. What if it's the modern folder market that was in a bubble? Maybe it's just me but I feel like the modern folder scene has gone a little stale and slowed. I think people are over saturated with modern stuff and naturally turn towards traditional knives.
For example I don't necessarily think that the problem is just that collectors not selling, but rather people who own only a handful essentially taking knives off the market. Whereas before collectors traded back and forth with each other, now random joe who is just looking for a knife can come in and buy it, only he's not going to eventually put anything back in the market.
Anyway just my worthless two cents.