I have a painting of a commuter train I used to ride to work every day. It's not a conversation starter (or rather, I'm always the one who starts talking about it) but I love it because it reminds me of when I discovered that I didn't need to be a slave to my car and how freeing that was.
It cost me $50 and I've taken it with me every time I've moved.
I really don't get dropping thousands on a single piece, I've never felt any work speak that loudly to me.