I did the clutch on my '85 2M4 5 speed and it only cost about $150-200 Canadian for the clutch itself. I suspect that a v6 clutch wouldn't be much more than this.
Some advice:
Fish it out with a piece of thin wire and then sit down and have a good swear and another beer.
I found the clutch to be a tough job with a very steep learning curve but it is do-able and would be much easier the second time.
The main problems I had were:
I fiddled for long time and then I finally just wrestled the trans off the engine after tilting the cradle down at the rear as much as I could.
I never actually got the trans out of the car, but I did have (extremely poor) access to the flywheel/clutch and I changed it anyway. This was a miserable job but I got it done. I suspect that the V6 might actually be a bit easier to work on since I don't think that it is as long (from left to right) as the 2.5l 4 cyl. This might give you enough room to not actually have to remove the cradle to get the trans out of the car.
From: Peter Frise