Congrats.
I test drove an 03 M3 cabrio w/SMG, Nav with about 4k miles and they were asking $58K (probably was about 60k new). I don't think they would go anywhere near the low 50's. Seems like it's a real application of supply and demand against how long they want to hold on to the car. As the salesguy said, "This isn't a car museum." (LOL). Last I checked it was still there, but I'll check when I pick up my car.