I would ring a motor factors and price them yourself. Also ask the garage are the genuine parts and make sure you price like with like. Then you can make a decision on it.
I think it sounds excessive myself but it has been a while since I had mine done (toyota corolla) but don't think I paid anywhere near that.
I got my car serviced few months ago at one of those atlas garages and they did a very good job. Very reasonable too.
Seems very expensive... you should definitely ring around... fastfit / advance pit stop - places like that do that type of work aswell... just give them a call & get a price...
I'm getting my rear disks/pads changed on my Peugeot 307 next week. I got Pagid Disks and Pagid Pads online delivered all in for €89 (Stg £76) and I guess it'll be an hours labour to fit them.
Perhaps get the parts yourself and go to a local independant garage and get them fitted.
I got a similar call from a Toyota dealer while it was being serviced, they wanted €165 to replace the rear brake pads. I said no and when I got the car home I checked them and the pads where only half worn. I got another year + before they needed replacing. I purchase good quality pads from the motor factors for €40 and the local garage fitted them for €20.