I've bought some books so many times over the years I've lost count. Like The Hobbitt and LOTR.... read The Hobbitt for the first time in a library, and then purchased it numerous times over the years from paperback to hardback to special edition. Same for LOTR, although I never bothered to read those books in the library. That's what makes ebooks such a good deal for me, I don't think that my epubs will wear out.
And to continue with the poll, there are a handful of authors who I love so much that I buy new - at list price even! - with or without any sample reading. Although now I am getting well on into middle age, some of the favorite authors are now blessed memories, and others are not far out
As I am not quite as prolific a reader as when younger, learning to love new authors is a little harder for me.
Vic