Rare book with sky high prices are sort of the norm in this hobby. The result of this is that I buy a fair number of books upon release, even ones that don’t 100% interest me, because buying them later will be impossible. For example: a guy on gunboards is about to reprint an updated version of his carcano book. It will be pre order only, with no extra copies. In all likelihood there will be fewer than 50 printed. When they are gone, and you want one, then what? A $100 book becomes $350, if you can find it, so it might as well not exist.
I open my library to any of my friends that have questions, as I know my book collection has a lot of rare titles that are hard to locate. It’s just part of the hobby to me.
I don’t like that my books are valuable, and I’d love for everyone to have their own copies, but that’s just not the nature of this hobby. So many book are privately published because no one really wants to find the startup costs.