My dealer quoted $225 for the service today...
I asked if that was a hot flush to get the converter done too.
That was just for dropping the pan, changing the "filter" and adding 8 quarts.
The hot flush was "gonna be about $500".
No thanks, my local/independent transmission shop (with a ton of 6.4/5R110 experience) will do the hot flush for $250+.
I'll be doing my shortly and adding a Mag Hy-tec high capacity pan and DieselSite remote bypass filter when I'm at it and should be able to do all that for under $700.
At power levels below 600 RWHP that should be all I need, and I don't beat on my truck either so I'm not planning on a built tranny, just good service/fluids/etc.