[Conman]

let me get this straight
Ford has the tranny out already, fixing other stuff, while the guy has it all apart anyways he notices the seal leaking and wants an additional $800 for just the seal? did he put it back together anyways and will have to tear it apart again?
I am assuming he is talking about the one in the input bearing retainer, it is the only seal in the front of the tranny. It is 4 bolts to take the retainer off and then a simple seal change (that is if the tranny is already out) I bet you could find just that seal for like $20. Actually, I can't remember off the top of my head but you my need to change the bearing to get at the seal but I don't think so, still not worth $800
as for the $250 rebuild kit I'm assuming jeg's would be similar to D&D Performance rebuild kit, it includes seals as well as all bearings, syncros and many other small parts. If you get someone to actually crack the tranny open to replace all the parts that come in the rebuild kit I could see it costing $800 but just for that one seal it can't be that much
I don't think I'd drop $1000 for a new tranny just for one seal

For some reason the mechanic may think he needs to crack open the tranny to replace that seal but he doesn't

hope everything works out for you