Blimey! That's a fair bit of money.
I'd have thought not, but I've only ever had one automatic (Sierra DOHC) and I did nothing to it, so I've got no relevant experience.
5K doesn't seem a very large excess of mileage, though, which might suggest that the fluid's service age is not the only issue with it. Perhaps a fault is putting wear debris in the oil.
I can only make the fairly obvious suggestions of going on any special-to-marque forums, and/or taking it to a transmission specialist.
Might also be worth posting to a US-based forum which will have more experience with automatics. I'd suggest BITOG, which is quite active.
Post a picture of the oil on the dipstick/in a container, and perhaps drip some on paper (blotter test). They'll like that.