Yeah I just misunderstood your question. I'm surprised that part isn't in the writeup, little strange.
As Billy had in his past thread, the dealership replaces the entire half shaft which should include the green cup/jack shaft. This would require dropping the diff which would add hours of labor to the cost. Maybe thats why the dealership charges $850/side?
Regardless the EMPI half shafts work great for $60... as long as you don't need to replace the green cups