Lloyd,
You will probably receive more responses if you post start a separate thread but when it's been asked before prices vary from about £400 at an indi in the sticks to £1,000 from a franchised dealer in the SE. There is a non-critical rear belt that I think drives the fuel pump and people say it's best to do this at the same time.

Site sponsor Guava get good reviews for customer service and they are in Guildford but wouldn't expect them to be the least expensive somehow  2008 MY Java Black TDV8 HSE