Dave, seems an ok price to me mate - my cambelt/plugs/AYC change cost me £525 back in February.
The stories about garages are horrendous. My bro did two weeks with a BMW dealership on school work release and one car they worked on was a 3 series Cabriolet. All they did was change the oil, then took it out for an hour with the hood down, stereo blasting and wheel spins everywhere - then charged the customer for a full service !!!!