That's interesting information, Chuck; it puts a wholly different perspective on camera changing (upgrades) than might otherwise be the case. I get a sneaking supsicion that that may be the incentive driving such pricing schemes/structures. And possibly why independent repair shops have had a tought time getting official spares. New camera sales are key.
The cost base is going to be significantly different.
Someone has to disassemble the camera to the point that they can replace the camera and then put it back together again.
That work is likely to be done on-site in a facility such as the one in Los Angeles, so you're not paying for cheap Asian manufacturers but for expensive American service people.