I was told by the shop that did mine that it was the best fitting aftermarket kit they have ever worked on. Required very little extra work to install. I think maybe the skirts required some fiddling around. I can not honestly recall how much I paid, but I am thinking $5-6 g's at the most and that's Canadian.
I went through all the Amuse threads here and made up a binder for the body shop to follow. I have summarized all my finding in the following thread.
Carbon fiber amuse install help needed
You should take your car out of the shop you have it currently in. They do not seem to know what they are doing.