This is one of the reasons why I have set myself a $1000 per piece limit on my purchases. Also, it's one reason why I have shifted more toward modern stuff. I think the modern stuff has a future when the current fans of those books mature. But, the older stuff is going to top out, for non-special pieces anyway. Look at the GA market for run-of-the-mill panel pages compared to the Bronze Age marvel stuff right now.
There is a demographic wave effecting prices, and there is a certain amount of spillover caused by speculation.
If the OA market collapses, my family won't be stuck with pages that they can't get a fraction of what I paid for them. I enjoy them, but when I'm gone, they may not want them.