The basic virb is 104 on amazon right now. The virb elite is still like 250.
I have the virb elite and the extra features are not quite worth the price tag when you can get the SAME camera specs for 150$ less, and if you are spending 250 on a camera I would go with the fly6 camera.
And a rear facing camera that stops recording when you are stopped...it would be very sad if someone rear ended you at a stop sign or stop light and you have your camera set to be off. Or if you have an accident and the camera only catches the accident and none of the post accident conversation/events because your bike stopped moving. Just saying
Also check out the rideye.
As far as seat post or saddle mounts....I know k-edge makes a saddle rail mount, personally I think it is kinda ugly. Any gopro seat post mount will work as well.