It's not just a financial issue, it's a SPACE issue - you can shelve three paperbacks in the same space a hardback takes up.Books are like gases, They expand to fill all of the available space.
My house used to be a mess with them. I am in the process of moving to strictly electronic books. New on the market this month - a thin seven inch linux tablet with a ten hour battery life.
Not that all of the black and white Electronic Paper readers with two weeks worth of battery life aren't great too.
Newspapers are bulky to carry, and hold so little information comparatively.
About three-quarters of the books I own are out-of-print. I have to really like an in-print book to keep a copy at home. The library has a lot more space than I do, and now that ours has on-line requesting, anything I want to re-read is only a few clicks away.