Yikes, dude. 6 years and 156,451 is some pretty heavy duty driving. I've been having some grear shifting irregularities recently too, namely less-smooth shifting and a sticky shifter and grinding feel as well. I'm only at 77K though. Some folks on this board told me to check for shavings and check the fluids and lubes as well, but I haven't gotten around to it yet. (Funny, today was a relatively warm day--60F--and the car seemed to shift pretty nicely).
Who gave you the first quote, a BMW dealer?? I was wondering about the cost of replacing a clutch, and I was hoping for something in the $1000 ballpark. So the "ex-car dude" told you 1K for the transmission, but how much for the clutch replacement??