Passenger side mirror housing needs to be replaced on 2010 Lexus ES350

There is a hole in my passenger side mirror housing. The mirror adjustment still works. But the dealer insists that the whole mirror needs to be replaced, and they are charging me for $500 for the parts and labor.I would like to have it confirmed and thanks.

Asked by for the 2010 Lexus ES350
I think, nuts and bolts, you got screwed. Sorry.