Yes, I still buy music (CD & SACD).
When: I usually buy just after the disc is released (as you well know, most classical labels advertise upcoming releases about a month in advance, so I've been salivating for a while when they finally release them and bite right in.)
Why: I love having physical media. I enjoy going into the spare bedroom where I have my music collection. I get to see, touch, read liner notes (usually when listening, which is really big for me....I love getting a deeper understanding of the work, the artists, etc.--kind of like special features on a DVD/Blu-ray) and I can get inspired when I see something I haven't heard in a while. I have my own library, which I re-organized just recently, which makes me feel as happy as a little boy who lines up all of his Tonka trucks and Match Box cars to take a look at them all.
Music in your cart: I heard that!
Why buy? I love music. I want music. I need music. I don't want it somewhere "in the cloud", I want it in my hands. Which actually has created a new issue. My wife and I have no one to inherit our collections. I plan on looking into who I could leave the music and movie collection with once we're both gone....I would hate to think it would all end up in a dumpster in the driveway when they emptied the house.
(what I said also goes for movies: DVD & Blu-ray, library in the living room)