coronoskae

I have 2001 Legacy outback sedan I bought used. Unfortunately at the time I purchased I did not notice a small area where there is a piece of rubber missing from the sun roof. It is perfectly centered and very smooth, so I figured some piece fell off and I could go to a dealer and get the piece. Maybe it was my dealer or parts guy...but they said I needed to replace the whole roof (glass part) for $400... I feel that they are yanking my chain if not worse. Any thoughts?