Gary,

Get a new mechanic.  I'm not meaning to offer your mechanic if it's a friend
but that quote is a little outragous.  If the leak is in a hard steel line,
you can cut it and double flare a nut on both ends with a union in the
middle or male/female connect the splice.  I have found that using the union
seems to be a little more sturdy but it all depends on your ability to flare
the lines properly.  Either way, if the rubber line from the caliper to the
hard line, proportioning value or ABS is gone, you should be able to get
that line for $100 or less.  After the line is replaced, you will need to
bleed the brakes with fresh fluid.  I would do it myself but if I wanted a
mech to do it, I would get the replacement line and the brake fluid and ask
him to quote on the labour.  To replace the line or repair the hard line and
do a full bleed should be a 2 hour job tops (likelyless than that).  Assume
on the high side that the dealer would be $90/hr (CND) so figure $180-$200
on the labour side and another $100 plus or minus for the line costs.  I
would say $300-$400 would be what you should pay at the dealer.  I'm sure
I'm about to get my head torn off by some dealers and ASE techs, etc.
Perhaps I'm off base here...  Maybe someone can check MOD for a brake bleed
(ABS may be a little longer or more involved as they need to pulse the
modulator/line).

Good luck.
Andrew.