I would get a second opinion. I think they are hosing the guy. I've never had to have a clutch replaced, but a Mirage clutch kit isn't priced much differently any other car like a Honda Fit.
My dad had an estimate for over $2000 for repairs that were done somewhere else for under $200. They weren't even honest about really needed to be repaired & that was at a GM dealership. Another GM dealership he trusted more did the correct repairs for under $200. He later went back & let the other place know it, too!
If you don't know much about cars, I would get quotes from a couple different places on big items like this.