New cap and rotor???
 

Hello,

The cap and rotor both appear "damaged" the contacts are rough and slightly blackened but the car idles smooth and runs fine. Will changing these parts make a difference in performance and/or fuel economy. Should I just spend the $140+ and change them?

It might not make that big a difference in the performance, but it will lower the strain in the ignition system since the electrical paths will be easier to bridge.