New brakes on my vehicle

[*rfaulk34*]

Sounds a bit high but you have to take into consideration how long it's been since each has been changed. Since they were grinding, sounds like it's been a while. Most of the cost should have come from labor and if the bolts were hard to get out--not knowing what kind of tools your friend has--it will take longer. 

I've had varying degrees of difficulty with "stuck nuts" on all different kinds of cars. 

Your issue isn't so much that he charged that much, it's that you didn't find out how much it would be ahead of time AND that you didn't shop around and buy the parts needed, then allowed him to put them on.