Well I don't think it's fair to call it parts killer when you have been driving for 40 years and you never bought new, so original condition unknown.
But...
My most expensive and biggest trans was my 10 speed in the freightliner.
It was supposed to cost around $6500, but I found a shop that had the mechanic doing jobs on the side and the transmission for $2500 no paperwork but he gave me his word for a year warranty, 3 years later I got no problems.
I installed with my friend so no cost there.
Broken a few transmissions and toasted a few as well.
Th400 in my 75 wagoneer, had a bad angle on the cv shaft and it broke, whipped up and broke the case and dumped blood on a snow run.
Th350 in my 79 van, revved the engine and dumped it in 1st with 12 guys inside and broke the slip yoke in the tailhousing and dumped blood on the snow on new year's eve.
Broke the bellhousing on a couple th350 4x4, and 2 tailhousings all on the same blazer. 4 instances total, also fried the clutches on a 5th transmission after I drove it home with the fluid in it.
Roasted 3 th350 in my 78 monte carlo.
Had to go home in reverse every time.
I have stripped a few 10 spline sm465 output shafts and couplers and destroyed an np203 tcase.
I have fried a few clutches but only one new one within a few months from rowing gears in a mud pit, back and forth until I finally got out, on the way home pieces of metal and springs were falling out.
The rest was just normal wear, little faster than the average guy but still few years per clutch.
I have destroyed a couple of Peugeot manual transmissions.
I am in the process of opening up a 2003 Mitsubishi eclipse gt automatic transmission which just suddenly quit 6 months after a rebuild including a new updated pump. That was the same symptom before the rebuild and the pump had just broke.

That's not too much is it?