Since no one has responded, I'll open.

The rear shaft seal is pretty easy, but you can tell if it is leaking by
looking.  If you have the right puller,
you can get that seal out in a few minutes and tap a new one back into
place.  Id estimate $50 or maybe
somewhat more, unless you go to a dealership where they charge high and have
generous flatrates.

The pan gasket and filter... About $75 -90 at a typical independent shop,
according to my last estimate.
More if you let them suck out all the old tranny fluid with their sucko
machine and replace all the fluid.
You could do it yourself for about $25 for the filter and gasked, and maybe
$15-20 worth of tranny fluid.

Front seal.  Depends.  Hard to get to, they have to drop the tranny.  If
they can pully the tranny body without
having to take off the bellhousing, it is an easier job.  On some cars and
trannies you can do this, on others you
cant.  Without checking flatrate times or parts costs, I would estimate
$150-350.