Professional comes from standardized connections that are widely available so you could interchange
simply, fast and reliably.
Setup that i made is all custom. So it will work for me but not to the other person.
That is the main difference.
And professional stuff do not blow up or make fire most of the time.
This is why i ended putting some silicone on my battery terminals. 20 amps could introduce nice fire
if shorted

Also what you have to consider is additional gear: evf, monitors, audio stuff.
They all will eat up your initial 2 hour mark and leave you maybe say 40 minutes or less.
So geting pro batteries have a lot of advantages despite their price.
If you earn money with them then time is essential. If you are hobbyist then your time cost nothing and you can build or use what ever you like that is in specs.