£289 for the op sounds pretty reasonable - even with a mate providing me the cam belt set and getting it done at a trusted local independent it still worked out at about £200-250 for me (can't remember exactly now, was the start of the year). All that faffing to get to the cambelt. The local stealer wanted £450.
My mate also advised me that it's worth considering getting your water pump replaced at the same time - it's the same lengthy process of dismantling to get to that should it fail at a later date, so apparently VAG dealers working on the 2.0TFSI advise you to replace both cam kit and pump together.