Often time the lines need to be custom fitted to the vehicle, and you wont find a specific labor cost for this repair. This is a job that a shop needs to look at to determine the labor time to replace or repair the line.
Actually, I just did this myself... it is not really that hard.... all you need to do is remove the old brake line and bring it into your auto parts store... they will have a rach with brake lines, just pull off a couple of the right diameter, and lay them out to get your length... then get a coupling (if you needed two) and replace the brake line.... use a can of WD40 as a fulcrum to bend the brake lines to the proper angles (using the old as a guide)if you do not have a tubing bender... Use zip ties to hold the brakeline in place where the old clips were(if necessary),then bleed the brakes and you are done... use a can of brake parts cleaner to clean off any brake fluid from around the wheel and that's it....
the brake lines should cost anywhere between 5 and 8 dollars.
so - with the brake fluid, can of brake parts cleaner, lines and coupling, you should be looking at about 20 to 30 dollars, plus about a half hour to an hour of your time.