All my (long) life, have been buying books. Each time we moved, had to cull and donate, but still the collection grew.
Obviously, it is limited by bookcase/wall space available. When I have to get rid of some, it is with great regret and anxiety, but I find many were not all that great, and they go first. I still have hundreds of books I bought many years ago, and keep and often re-read, just because they are great.
The old Rocket eBook before, and the Reader now, solve the problem of lack of space for any new tomes. If one I get for the Reader is particularly good (such as "The Kite Runner" I recently finished), well then I hie myself to Amazon and buy the hardcover version for my library.
If I had enough $ I'd just build an adjoining library to my house. An expandable one, that is.
