I do not want to comment on price. I have been doing quality auto detailing since 1970 and I am a Concours judge and a member of the Mercedes-Benz club of America.
Touching up silver metallic paint is not what you expect. You can not get the same effect with a brush stroke and a dab of paint as when the paint is adomized and sprayed . The metallic stands up on end creating the metallic effect. When done with this method and also receives a light coat of clear paint to give it that gloss and protection.

It done properly you should have a hard time seeing were the damage accured. Good workmanship is an art forum and not easy to do just looks that way.

Bob Geco
Bob Geco's Auto Appearance Care
Los Angeles, CA 90034