Damage to rear bumper, replace?

I scratched the left side of the rear bumper of a 2010 Dodge Avenger. The damage was pretty superficial with slight scratches that seem like they could be buffed out and one larger scratch that did some damage to the paint job. I have been asked to replace the bumper by the owner although various repair shops have given me a $400 quote based off pictures of the damage. Is there any reason for me to have to replace the bumper based off the damage?

Pictures of damage:

http://s1268.photobucket.com/albums/jj580/maggiemms/?action=view&current=photo.jpg

http://s1268.photobucket.com/albums/jj580/maggiemms/?action=view&current=photo-3.jpg

http://s1268.photobucket.com/albums/jj580/maggiemms/?action=view&current=photo-1.jpg

The bumper doesn't look too bad. It should be repairable, though it looks like there is a gap at the top of the bumper below the lights. Are the clips damage or just popped out? I would say worst case scenario is that you get a bumper cover. Some of those shops will try sell you a bumper assembly which is more expensive.

-J