Hi Rhino, not sure where you are based but the man for any 3.2 timing chains work is Gareth at VAG Auto Care Services in Lincoln. Won't cost anywhere the amount you were quoted by Audi. He has done many timing chains replacement jobs, he's quite well known in the VW / Audi scene for working on the 3.2 engine. The best way to get access to the cam chain is to remove the engine so at this point it's usually wise to change the clutch as it will be exposed and accessible when the engine is out, so it is worth considering a clutch replacement at the same time. He is just in the middle of moving to new premises and will be up and running in about a week's time I believe.
Call him on 01522 694560