It sounds like you had the installation done as opposed to DIY. My
numbers were all DIY.
It would be interesting to see the breakdown of parts and labor. My
guess is that the installer up charged the parts costs.
Hitches are not that hard to install. I've done at least 5 on my own
vehicles and helped a few other people with theirs.
I installed one on my wife's Jetta - to carry the bicycles only.
It is custom made for that car ; comes with clear instructions -
- torque values & such ; and I'm not very mechanically
inclined - I barely know which end of the wrench to hammer on.