727 transmissions are so complex

I have been studying the books from Munroe and Hand. The information is so overwhelming that I hesitate to begin an overhaul or rebuild. Can you give me a great reason why I should do this myself instead of getting a TCI trans and call it good?

I am building 500+hp 512 ci stroker for my 73 scamp. I was a machinist for 12 years in my past life so i can do it. But why would I want to?

The options are to spend $600 for the kits to rebuild and replace the valve body for strip use.
Or to buy the TCI trans to do it for me. What does your wisdom say??
Another possibility is, if you are near a community college that has an automechanics program, you can take an automatic transmission class and rebuild it in class. My friend did that with good results.