I am also an Audi driver and use a local Audi / VW specialist (AVW Autocare, Gilmerton Road, Edinburgh).
They charge £55 per hour plus VAT, but they are excellent, have done some things FOC for me as well as saved me a pile of cash on items like the (fucking shitey) Audi Pre Sense faults.
Not the pads, but another big job - last year I got charged £550+VAT for supply and fit of the Timing belt / Water pump kit. Based on what I know is the Main Dealer cost, that was pretty reasonable.
Main dealers are daylight robbery.