One of the big charity opshops in my suburb has the most amazing book section I have ever seen in an opshop. It's big but not too big, and roughly sorted into paperback fiction, hardback fiction, kids books and several non fiction categories. Nothing is sorted by author, but it's small and well presented enough that you can scan each row. Every month or so, I spend an hour there on a Saturday afternoon by myself checking the shelves at leisure. This weekend's haul was pretty good. Some novels, a feminist non fiction title, a Richard Scarry book for Grace when she's a bit older.
This way I can keep the book for as long as I like. Most books don't find a permanent home here and either end up on a market stall, given away or returned to the opshop.