Regular price $380. $323 with promotion code "RANGE."
I have been using one for a few months with the Picatinny adapter on pistols. More expensive than sky screen chonographs, but I wasn't using mine because they are a pain in the hind-end to set up. It takes maybe 30 seconds to clip-on, or strap-on the Magnetospeed "bayonet" and plug it into the box, and that's pretty much all it takes to set one up.
There is a cheaper Sporter model, but it isn't compatible with the Picatinny mount.
I'll probably write up a review eventually. Real short story - I use one, and I like it.