studied an oncology degree and then continued post grad, we were taught to use primary references over text books? I only owned a couple of text books, one of which was Grays anatomy that was gifted to me by an uncle, in all honested it wasn't that useful but I have just looked it up and the OP has opened my eyes its now £150! Crazy indees
Yeah, I can see where that would especially be true in a medical field. Hard copy books would tend to go obsolete rather quickly.