I buy most of my books second hand (or even third or fourth hand for all I know!)
In fact I buy almost everything second hand.
I actually prefer used things. I like the feeling of continuity. I love it when books are written in (I mean a dedication on the fly leaf, or if they've been annotated for someone's schoolwork, or someone has marked a passage which has special meaning for them).
I can't understand why people have this obsession with having everything new and shiny.....characterless, I'd say.