I have no heat- and was told I need to have the blend door replaced.

If that indeed is the problem, I can see it costing that much. More than likely they have to remove most if not all or the dash to get to it.

I priced 3 mechanics around my area and it was all similar to around $900-$1100 for parts/labor. The part itself is cheap, but the labor is very extensive. Good Luck