I purchased a complete kit with wiring in US and installed it myself on 4.4 2006.

$750 for the hitch and installation is not that bad. $300 parts+$450 labor for 3-4 hours-- your call. Wiring kit cost less than $200 and it takes 30 minutes to install. My car did not need any reprogramming. There were multiple posts from others that programming might be needed.

It sounds like they are charging ~$400 for the programming or "pleasure" of dealing with them.