I still have loads of books and almost as much "loose" sheet music which I've downloaded or been given at workshops, gatherings, or to prepare for concerts.

At the moment, I keep a couple of folders containing "special tunes" which include my favourites and others I especially want to work on at the time. Unfortunately, these are becoming a bit full too.
Of course, there are several hundred and more which I have learned but don't have immediately to hand any more.

However, I learn tunes by a variety of means and would never treat the written notation as "gospel". Even if I felt obliged to "play as written" for a particular performance that would just be a "one off" and I will always end up doing it my own way in the end.

I still buy books and CDs(see my more recent thread) although not as often and it's usually because I want to support the composer, performer, or organisation. Quite often, I'll only learn one or two tunes but it's the thought that counts. ;-)