I have a pretty good bunch of other shooters' original prints, and a LOT of money sunk into photo books (not all photographers live by selling individual prints!). One the wall are mostly my own, along with other works like computer graphics and posters for movies I worked on, and paintings by friends. Biggest bid so far from me was $1600 (ultimately outbid, *sigh*) last year for this print. But as I say, there are many ways to subsidize the arts beyond just buying prints. I do agree that looking at fantastic prints is a fine way to improve your own printing (likewise for drawing and painting, btw). A book reproduction doesn't have the same tonal range and issues of scale and immediate materials vanish from reproductions (shining example: all daguerrotypes).
A couple of other thoughts on this here, especially toward the end.