Reminds me of that time I found a book at my Uni library that was in the rare books collection that I could only read in the reading room and then saw there were many copies on AMZN for 50 cents + shipping.
But it will also be out of copyright so the cost of getting a “new” copy is basically just the cost of printing.
https://www.amazon.com/Discovering-Secrets-Happiness-Intimat...
Not rare at all but some people might say it has some prurient interest (talks about his sexual misadjustment) so maybe they think it has to be limited access or maybe people will steal it or something. (The same library kept Steal this book in a restricted area of the stacks but let me check it out.)