So the breakdown of costs from local indys is -
Genuine VW parts inc Cam belt kit, water pump, antifreeze/corrosion inhibiter, sundries, environmental disposal = £205 (checked and seems correct)
Plus 3 hours labour. Local indys (reputable ones) charge from £64 - £78 per hour. VW about £90 - £110.
Apparently Mk6s are more expensive than Mk5s and diesels more than petrol.....