Parts.com OEM Bumper cover, front AMG, w/o washer $450.80. Ask them on shipping cost.
Carstar will paint it for about 3 bills. Takes about 20 minutes to remove, about 20 to reinstall.
You will have to transfer some parts from the broken one to the new one, ie. fog lamp mounts; fog lamps; temp sensor; bumper mount studs (drill out three rivets each, replace w/ small stainless hardware); bumper mounts guide on each side, same trick w/ the rivets; inset wrap-around bumper pad.
The CLK OEM bumper cover is PUR (polyurethane) not thermo-plastic, so it doesn't respond well to heat--it liquefies. Thus, plastic welding can be a bit tricky. About 90% of bumpers are thermo-plastic. Beads are blown into a mold, then the mold is sealed and heated, forming the bumper cover. These respond well to plastic welding. About 10% of bumpers are polyurethane. Two compounds are poured into a mold, forming a third compound which hardens without heat, forming the bumper cover. Not good candidates for plastic welding.
Many non-dealers will install re-manufactured (repaired) PUR bumper covers. There are many suppliers that repair these PUR covers and market them to repair shops.