I'm sure this is true in many cases, but I suspect (with myself as an N of 1) that some collectors are merely hitting a point in life where they've got a couple dozen or more long boxes of 40-plus year-old run books and minor keys and thinking, "If I unlock all the $10 bills in here tied up in books I don't remember or care about anymore, I can get a few of my grails." That's what I have been doing: downsizing lower price point items I long ago lost love for, and putting the money back into things I've always wanted. I still have plenty or run books, but a lot fewer, and none of the ones I knew I was never going back to. And more keys, cool covers and other pricey obscurities I've always wanted. From that outside, my curating can look a lot like the flippers, I e's probably more of them, but also probably more than just me curating in this way.