I moved a few years ago and decided to sell a lot of books. I scanned the bar codes for about 50 and tried to sell them on Amzn. For my technical books, I learn

I moved a few years ago and decided to sell a lot of books. I scanned the bar codes for about 50 and tried to sell them on Amzn. For my technical books, I learned that not matter how valuable the books were to me, they were worthless. However, I had some really valuable gems. One was a thick book of old Japanese lithographs, the explicit kind called "shunga". I sincerely don't know how I came to possess this book, but I sold it for $250. Another was self published by an old friend about his experience in the Seattle of the late 60s, which sold for $500.