This equates to 1 hour of labor at $75/hr.

The cynic (actually, I'm an 'experienced optimist') in me says be sure this is a square deal. A sleazy shop can wipe the valve cover, park it for a few hours, give it back to you otherwise untouched, charge you the $75 and you may not be able to tell the difference.

This is also known as a 'wall job.'

Otherwise, it sounds like a reasonable price for the labor involved.