It came built in for our controller. The camera is $1400 from fanuc and the cable another $1300. But the camera is just a commercial off the shelf Sony SC56 that you can pick up used off ebay for like $60, or new from a sony distributor for like $400.
They wanted $13,000 to add a multiplexer for multiple cameras, but Sony is kind enough to publish the specks for the camera with the pin out and cable plug part numbers ect and fanuc outputs the frame sync signals; so its trivial to build your own multiplexer driven by digital outputs on the robot. Just be sure to power the cameras from a separate 12v source.