Rotors and pads for w126 are cheap. I had the front one done on my 420SEL for about $150 Canadaian, at the dealer including labour and tax. I checked my records and the last time they wer done on my car was 5 years and 45,000 miles ago. They last, have great stopping power and are cheap. These are really great brakes, unless you plan on racing I don't know why you would need an upgrade.