As I recall my mechanic charges four hours to change the exhaust. That's usually two manifolds AND two risers for a V8. While the manifolds are off, starter should be only a matter of minutes, probably priced at half an hour. The current gear reduction/permanent magnet/high torque starters are actually pretty easy to change. They're light, making them easier to position and hold in position to start the bolts, and the smaller motor portion allows a little more wrench room.
