Good luck in your search! I always wanted a 928, just for shiz and giggles...but i doubt it'll happen.
You think you want one til you actually own one, then you can't wait to get rid of it. My friend picked up a 86.5 928s and put 11 grand worth of work into the car just to get it running. I'd say 80% of that was into the engine alone, which aside from sending the heads out to a machine shop, he did all of the labor on. Its NOT a cheap car and its NOT a reliable car.
It does sit well next to my 745i though, if you were a drug dealer in the 80's this is what your garage would look like