While I haven't seen the estimate, there should have been some remove and replace charges for the lights, and the amount of painting they had to do would be dependent on how easy it is to match the paint and get a good blend across the entire bumper. That looks like just plain black versus Obsidian, so the paint would not be as expensive. That does not sound that much out of place to me for a MB certified shop. They had to paint the trunk lid on my 2023 and it was around $2200, but there was a lot to remove and reinstall, then replace the chrome emblems and lettering on the trunk lid. The lid had to be removed from the vehicle to paint, etc.