Mostly you'll need the M2, which is around $1,750 assembled from http://www.makergear.com
. Of course, if you don't have an M2 (or similar 3D printer), you also don't need a camera mount for it, do you?
The other parts:
One of the USB webcams like the one shown. They come in a variety of colors and are sold mostly from China via eBay for about $6 to $8. The advertising generally claims that they are something like "8.0 Mega USB Web Cam" -- but basically they deliver either a 320x240 or 640x480 video stream that can be scaled in software to be bigger and correspondingly blurrier. The image quality is lousy on the 320x240 version, but the higher resolution one is actually pretty good, and in either case the form factor and lens view angle are excellent for this use.
A little piece of 2-sided (carpet) tape or a hot glue gun.