Auto body repair & detailing: refinishing a scratch, old cadillac, mobile paint

Question
Ballpark, what is a reasonable price to pay to  fix a 3 inch long, deep, scratch on an old cadillac, paint newer, if that makes any difference, in your professional opinion? Assume a custom color as this would most likely be the most expensive paint.  

Answer
A body shop will charge you quite a bit because of their overhead.  I wouldn't pay more than 100 bucks.  Contact a Mobile Paint Touch up outfit.  A local detail shop should be able to refer you to someone, or just use the yellow pages or Google.  They mix their own colors and a good touchup guy can do wonders on something like this.  If it's a show car, use the body shop.  If not, you'll probably be happy.