Thats ridiculous, I was under the impression the cambelt and water pump was fixed price of £650 at Jag? I tried a quote a few days ago on the jaguar website using my reg and mileage it's a 2012 3.0l v6s diesel 95,000 miles and a major service which includes the cambelt change was just over £1000. I've had various quotes from local garages online for £450-£500 for cambelt and water pump. Brakes I would do myself to be honest and have priced up brembo brake pads from GSF car parts (similar to euro car parts) for only £30-£35 a set, discs are more expensive and wear sensors but still shouldn't be anywhere near what you were quoted. I also want the gearbox service done, the ZF kit is about £250 but the process requires a ramp and diagnostic equipment to do it properly.