I have seen post on various forums where the local carpet person would do the install. In fact there was a post last week on one of the other forums where the person had his replaced for about 1/4 of your price. He had to remove all the furniture (coach, table, captain chairs, etc) for them to do the work. When I had the carpet replaced in my house I had to move all the furniture to the garage, although it might be harder to move stuff out the small RV door and you also have unbolt it all the requirement is the same. Also there were places (like at cabinets) where they had to cut the carpet instead of removing the items that were installed after the carpet. I am not sure what all the price includes from the factory but they might be including the labor to remove / reinstall everything.
From the pictures I think he had only one slide in the area where they replaced the carpet. They did the sides of the entry way and the step well cover as well.
We are not ready to replace the carpet in ours yet. In my last RV I went with Allure flooring and it worked out ok. However my wife would have preferred carpet. So on this one when I change it out I will be checking out the local carper places and the newer "pet proof" carpets.
Mike