That's a pretty good price.
Best quote i've had is from Stafford Audi (main dealer), they are advertising on ebay and quoting £249 inc VAT for a cambelt and tensioner change on any 4 cylinder VW, Audi or Seat (probably Skoda too). Not bad for a main dealer garage using genuine parts!
I contacted them, if I want the water pump doing at the same time it's £338 all in.
Someone on this forum put me onto it (see other threads). Will be getting it booked in very soon.