I’ve actually sold a lot of stuff over the years (and plenty of regrets lol). I did a lot of Greenberg and smaller local shows in NYC through the 90’s buying and selling mostly silver age and pre code horror back then (lot's of regret there .) I did pretty well at those shows for the time.
When Ebay and then CGC started I got most of my Golden Age stuff graded and gradually sold it off as the market rose through the 2000’s. I’d love to have much of it back to sell at today’s prices but I really can’t complain too much, because I got pretty much top dollar at the time (okay, I really regret selling my Human Torch 12 CGC 6.0 for $900 but that was about 2-3x guide when I sold it). Before Ebay, if you were small time, you were really at the mercy of dealers and/or whoever would walk into a show if you wanted to sell anything.
I never had too many pulps, for whatever reason they were not around too much in the world I traveled in back in those days, even though there were a ton of book shops and shows in NYC.
My paperbacks were another story, I sold nearly my entire vintage paperback collection to Jon Warren when I needed money in the early 90’s before Ebay. It was 5 or 6 long boxes, including a pristine copy of Reform School Girl and tons of 1st ed mystery stuff, Jim Thompson etc.. He gave the best bid out of a couple dealers I contacted, but I did keep a box of my JD stuff and science fiction that I still have today.
A few years after selling I started to buy paperbacks again and I’ve reacquired most of what I really wanted back, including a very nice copy of Reform School Girl that is only slightly lesser than the one I had. I don’t think I’ve ever posted it here, maybe I’ll dig it out.
I'm still picking up paperbacks when I find the right price/desire ratio and i've been buying some pulps because the posters on this board have ratcheted up the temptation levels, and they're a cool substitute for the Golden Age itch at a price point I can live with (meaning keep my marriage intact, lol)