Can you see the scrape viewing from the front? If yes, you should consider buying a new bumper cover and have it painted and installed. A new bumper OE bumper cover will cost ~$220.00 to $270.00. Plan on paying about the same to a body shop for removal, shoot and reinstall. Total cost ~$500.00.
If the AMG is not in A+ condition consider masking the underside of the bumper in an arch following the bumper line and paint in a deliberate different color. This you can do yourself.
Ah yes, you can see the scrape, nasty. Consider pulling the cover yourself and have someone paint it, may save some money. Remember the cost in sanding, priming and painting may be just as much as buying a new cover. They are not expensive.
BenzWorld.org forum is one of the largest Mercedes-Benz owner websites offering the most comprehensive collection of Mercedes-Benz information anywhere in the world. The site includes MB Forums, News, Galleries, Publications, Classifieds, Events and much more!