I have bought Doug Wead’s book so I can enjoy reading it without the pressure of getting it back to the library.
Always buy books to read and reread at my leisure or to keep as a resource book. Lots of those.
We have book cases full and more in stacks One day I might go thru and give some away but it would probably end up being just the book I want to check out something later. Buy very few fictions. Mostly history or current events.