I just had new hand brake cables fitted, including the casing (I don't think you can buy the cable alone?). The parts were about £15 each (there are 2 cables, with the split near the front of the car, very close to the handbrake mechanism) and that was for an Audi part. I didn't fit them, but the mechanic said it was a simple job and charged 30 mins labour. My TDi is a 2002 model with 80k miles on it. The work was done as it failed the MOT for a non functioning handbrake - due to sticking / siezed cables. Sorry I don't have the part number.
David