I got mine a few months ago thru someone on craigs. They were a brand new set, in the box, never opened. I did make sure to meet the person in person though. There were several ads that looked like scams and I avoided them. But I guess it depends where you live etc.
If I do sign up for Kaplan which I'm considering, they'll send me a new set and I'll try selling the new set on craigs and keep using the one I bough a few months ago.