Although I own (literally) thousands of CDs (and have bought hundreds of songs from iTunes as well), I have found over the years that there is little actual value in having a collection any larger than what you are practically going to have time to listen to.
People report crap like they have 80,000 songs (mostly stolen, of course) like that's supposed to be impressive. What would actually be impressive is if you could name them, or say you've heard them all.
I prefer music that means something to me. It's not an art form I think is better in bulk (come to think of it, no art form is better in bulk).