I scratched my car, how much will it cost to be fixed?

[Sammie]

So, I just got my new silver 2009 Jetta at the end of July. Just a couple of hours ago, I was backing it out of the garage when all of a sudden I hear a loud noise like I knocked over a garbage can or something. I open the door and to my COMPLETE horror I realized that I drove right along side my moms car, scraping both her and my car. With a wet rag most of the marks on my moms car came off she just has one tiny scratch barely noticeable. My car isn't that bad anymore either, however on the back of the car there is a scratch where all of the paint came off, it's not very big at all, maybe a 6-7 inch long scratch and is not very wide maybe 3/4's of an inch, so it's barely noticeable, but still I want to get this fixed. I mean, I just got the car I don't want to have to deal with this for 6 more years and every time I look at it it's just going to make me feel completely awful about what I did, thank god my parents aren't mad because it's not that bad. I asked my mom how much it would cost to fix however and she said about $500-$800. Is that a legit estimate? Can you tell me how much you think something like this would cost?