I actually quit buying CD's which I've bought many of over the years, but once I subscribed to Sirius and XM, I don't think I've bought anymore except for specialized CD of artist I really like. I would imagine I had a 400 or 500 CD collection since I had been collecting them since the '70s. But other than those full albums of rock and new age that I really, really love, the rest was all given to Goodwill just to clear them out of my house.
In regards to digital music I've been much more selective there, mainly buying New Age music that wasn't being represented on Sirius or XM. Some of which isn't even on Slacker. In regards to anything else I have no reason to buy anymore.
I think as we go forward the model for music and even movies, will be rent or buy access to a library. CD, DVD, Blu-Ray sells are down big time and I think we are already seeing this model unfold with the likes of Netflicks, Blockbuster Online, iTune etc. I even think as sells on digital content begins to slow, you'll even so Apple open its Library in an all you can eat fashion for a monthly fee. Right now they still are making enough that it won't happen, but it will eventually.