What are you actually getting done on the rear brakes ??What parts are they covering you ??
IF you are just getting rear shoe changed, i would say for 180 euro = £140 is really expensive. But if you are getting the drums, shoe, hand brakecable changd then i would say is reasonable
Brakes fulid should be changed every 2 years or so, may be that will be included in the service ?? When they change the brake fluid, they have to bleed the brake. Ask them about it
For calipers, the only hard thing is taking the brake line off, as it is likly to be rusted and be chewed when u r trying to take it off. But don't worry about the caliper just now, till you see high uneven wear on one side.
Ming