My opinion is the repair price is in the ballpark. The job is not 'difficult', just very time consuming. Also, remember that a motorhome repair ties up a lot more shop 'real estate' than working on a car. Someone has to pay for that space being occupied... Surprise..it's you!
I've been a mechanic all my life and even retired, I still do a lot of my own work unless it's some really heavy stuff. I don't pull wheels off RVs anymore. Lighter stuff (like engine accessories) makes it much more affordable to be retired as I take care of those items. People who haven't had the time to learn how to do those things just have to 'pay the freight'. Not putting anyone down, just sayin'....