friend trying to rip me off .......

First of all, that job does not even take 20 hrs. More like 10 max. If you can get away with 300 and learned a lesson , thats good. By the way, here on the East Coast , shops charge 80-90 per hrs labor rate. New car dealerships are upwards of 120, (my son is a Benz tech). We charge our customers 60 hrs at our small shop at home. And we do not charge List price for parts. Got all the work we want.