How much does it cost to replace the reverse mechanisim in my 325i? on 2002 BMW 325i

I went into reverse just this morning and it gave a nice big jerk. I have reviewed a couple websites and apparently 3 series BMW's between 2001-2006 have this problem after the mileage exceeds 100K. My car is just over 150K (150,003 to be exact).

Asked by for the 2002 BMW 325i
They would know how much , the forum you were on, no??