Seeing quite a few late - mid '90's trucks with 'bad' automatic transmissions (regardless of miles)

What are common issue(s) with these transmissions?

What's an average price to rebuild one of them?

While appreciated, no, I don't have the time or tools to do it myself. I can remove the trans if need be to save on R&R costs, but, that would be about it.

Just curious what the collective here says before I start calling around locally.

Thanks.