I don't know what if any kind of shop you have or have not but the rear seal is very easy to change yourself just mark the drive line so you put it back the same way.
Pull the yoke (it's keyed so it only goes back one way) pull the seal change it out. If you have more than 300K miles get the next size to compensate for the wear and tare.
If you go a shop shouldn't cost much only should take an hour, maybe $200-$300. Buy a seal and do it yourself $50.00.
I guess I should ad that if it's just a minor drip where you don't have to ad fluid, don't worry about it.