The clutch release bearing failed on my 1991 535i toward the end of last year. 140K and original clutch. Sachs kit from BMA-$275, labor at local tranny shop (excellent shop)-$300. I had them replace the oxygen sensor while the exhaust was out. Picked up the car the next day. The owner wanted to buy the car right there! Nothing else needed. Now I could have gone nuts and replaced a lot of parts while it was on the lift but they told me nothing really required immediate attention.
Paul