I've just had my cam belt and all the tensioners replaced on my V6 along with the alternator belt. (The only job I will always get done at a Vauxhall dealer). When I arrived to pick up the car they presented me with a bill for £365!!!.
After a not very subtle argument it turned out they were trying to charge me £125 to supply and fit the alternator belt on top of the cambelt bill As most of you know to replace the cambelt you first have to remove the alternator belt, so charging me labour for that was, well, cheeky doesn't cover it. The best bit was when the service receptionist said to me "It's a more complicated job than you would think Sir", to which I replied "No it ******* isn't, I did one myself two years ago". (I have a friend who used to work at a Vxl dealer and he borrowed the tools).
Anyway after 40 mins of arguing and waiting they came back with a revised bill for £279 all in, which was what I was expecting.
Point of this is don't let them trick you, as they all try it on given half a chance.
Anyway this is a picture of the removed components for those of you who may be interested. (And yes the belts really are that long )