Those are good points. I just stick to ones that look interesting and are popular - or preview it on The Trove (though if I'm going to use something in a game that isn't out of print, I always pay hard cash for it).
Also I'm a laptop DM, and I can't imagine DMing without one at this point - being able to have all my resources right there at my fingertips without piles of books (plus having the ability to use Google to answer rules questions on the fly!) is just too important to me. (And I never have to show any of my players the cover of an adventure module or book, so they never have any idea what might be coming...

)