Noob question 727 really low shift points

What should I be looking at for cost (without the driveshaft) for a 42RH? Are they fairly rare or would they be around pretty regularly?

I am sure different geographical locations all have their hurdles, but I paid $125 for mine out of the Pick a Part yard and that was with the large yoke and converter.
(fluid and any pan contents inspected first of course)
It came out of a front end wrecked 5.2 Dakota built before 1996 (hydraulic controlled years)
The local yard had 6 I think, and I started with the one that had the best looking fluid.
Then I put a Transgo stage 2 kit with the "Low at any speed" option in it.
So for the trans I would have to put it at 350 or so ready to go in.