I used to have thousands. I sold a lot of them. I now have hundreds. Maybe a thousand. A mantle full of classics and a corner with three standing shelves full of more contemporary works in a variety of genres. I once bought a garage full of books from a guy for $100. Probably a couple of thousand books. I made some good money on the resell of those until I got tired of selling through Amazon. Then I pulled out what I wanted to keep and bulk-sold the rest to a local used book store.