from what ive seen on their site, the cheapest setup you can get from them to have that follow focus on your dvx is 1485.00 including the follow focus- cine focus gear, and baseplate with rods.
..i bought all the parts(high quality) for about 40.00 to make the follow focus-baseplate and all.. including buying some stainless rods i just have to finish machining out the main bracket for it out of some great plastic stock i have... really it would only take about an hour, but im waiting cause i asked for a new high powered dremel tool for christmas from my wife, so id like to use that on it..
even still im in no hurry to finish it then .. a focus gear on a cam with such deep dof is near usless anyway, but i just thought it would be fun to build one ..espescially since it only cost me under 50.00 to build from scratch buying everything at retail.
for sure pending what you are doing they definitely have some sort of place and time to be on the dvx... im sure that if we had the money wed all have one just cause it looks cool. and i would probably get mine from jbk.