The fronts can be a right bitch, getting the leg out at the bottom needs some serious smacking with a chisel! Then the 3 bolts on the bottom wouldnt turn so needed to be grinded off! I wouldnt do them again, did them on an Octy VRS and i think the A3 has the same spec. The rears are dead easy!
I was quoted £150 with alignment from midland VW (obviously thats no help to you)