I have a 4L60E that I pulled from a car I originally bought for our son's first car. I drove the car home about 50 miles and it worked fine, but then our son changed his mind and bought a different Roadmaster. I parted the car out because I also discovered the frame was rusty.
The car had 310,000 km on it and I don't think this trans has ever been touched by the look of it, still the original GM converter in it too, so let's call it a core to be safe.
$100, can arrange delivery within about 1/2 hour of Winnipeg if you are patient. If I don't sell it, I guess it's off to the shredder with it but I hate to do that.