They're probably expensive at REI. I would look around. Mine friend has had one for a year or so. They're awesome. He uses it on his helmet when he rides his crotch rocket. We also carried it with us down the Oconee when we float the river for a few hours. We swim to the bottom with it and bang it off rocks. Don't let anybody tell you that it's not awesome cause it shoots HD with a great picture and, with the case, you can pretty much do anything you want to with it. We meant to take it out to River Rock and slap it under some rigs, but it just never happened.
My future sister-in-law (Amber's brother's fiance) has one too, and she put that on her helmet when we went skiiing. Pretty cool shots of people busting face actually
It's a cool little camera and there's ton of stuff you could use it for. Just gotta find the right price.