I would just take the fender off myself they are not hard at all to remove, and you could have it painted by someone I was quoted by a bodyshop to paint my fender that I always go to for $125, and yes they do great work. If you pay more than 200 to have it painted you are paying to much, 500 dollars is just ridiculous. That scratch looks like there is nothing you can do except to get it re-painted IMO.