When I find a recording that's really worth it, I buy the disc. Have to really love it though. Growing up before the iPod meant getting shafted, album after album, with one-hit-wonders: you'd buy the whole album and then bang! Total trash.
Of course, their were some exceptions: that's how I discovered tool. Undertow had just been released and I heard "Prison Sex," censored or course, on a college radio station. Bought the album just because of that track and loved the entire thing. But considering how often I got screwed, and that I don't really listen to Tool much anymore, that's not much compensation.
La Gioconda with Maria Callas: Worth It. RATT: not so much.