Torque converter crack

I bought a new converter from autozone. It was $84

Was about to get seal kit from eBay until you said that a transmission shop might do it with parts for $20
The seal kit is $30 online.....so if they would actually do it for that. It would be nice.
I asked them a while back to rebuild a turbo 350 and they wanted like $2000. Was surprised

As far as putting a new bushing in there. What does it take to correctly do it myself? Why do they fail so badly when doing it yourself?