Basically brand new -- used it once for testing and indeed -- it can detect radioactivity. I've kept it in a moisture controlled container in it's anti-static pouch so it's in perfect shape.
I was planning on building a full scale Geiger Counter but I don't have the time. Sparkfun has a revision that includes auto-reset and a switch but same functionality otherwise.
$130 and I'll pay for shipping (if in continental U.S. or Canada). I'll even include some Uranium Glass Marbles for you to test it with.