Yup, I think he meant rotors! Your car has 2 caps & 2 rotors, and they are NOT inexpensive. Further, they are not known to last particularly long on M119.xx motors. How many miles does your car have? Knowing that will help us better opine.
But you probably do need to change them...there's a great article here on the site to guide you through, check the "Do It Yourself" tab at the top of the page.
"If everything seems under control, you're simply not going fast enough" --Mario Andretti
1995 E500 street car
1986 Porsche 944 Turbo S track car