Some guys from Advantech were visiting today (to talk about exciting things like motors and stages) so I asked about the trackball.
If you want it, you'll have to call. Price is at least $115 (that may have been for a non-lighted one), and they haven't sold many. Original use was on an X-ray machine, which was used in the dark, so the light provided feedback on what the operator was doing.
BTW, industrial joysticks and trackballs have a wonderful feel to them - in a different class (in price and performance) from consumer models.
--Tony