We don't post a flat number here because what you're seeing on the door changes the job more than anything else does. A door that's simply walked off the bottom track with the track itself still straight is a different repair than one where the bracket bent and took the track out of plumb - the second one means pulling and resetting the track section, not just rehanging rollers.
What we can tell you is that Lovejoy is about 10 miles from our McDonough shop, so travel isn't the variable driving the quote - the condition of the track and whether the opener's travel limits need resetting after the door's back on is what drives it. We'll look at the door in person before we say a number, because guessing over the phone on a job like this does nobody any favors.
One honest note: if the track is bent in more than one spot, or the door's cable has come off the drum at the same time the track let go, replacing that section of track usually costs less in the long run than trying to hammer it straight and hoping the rollers track true again.