| That is not a bad price since the conductor plate alone is around $230 and the Tranny fluid is approx $80 (assuming they drained the pan as well as the transfer case - approx 7-8 quartz total) . Throw in the filter, and the pan gasket, connector, o-rings, magnet, etc, and $525 sounds reasonable.
However, did the shop overtightened the screw when they were inserting the new connector? So if that is the case, it was their negligence that resulted in you having to purchase a new conductor plate?
When I purchased the conductor plate from the dealer, they specifically warned me to NOT overtightened the middle screw since if i strip the thread, I would be looking to purchase a 2nd new conductor plate.
Since you had a leak, did you pull the transmission control module (passenger side fuse box) and check to see if any oil manage to work its way into the module? | 
