Is GP capped at 600???

[MysteryNotes]

I was watching some videos about gathering and collectables ect and I see that they have like 633 GP or so but I seem to be capped at 600..... What's up with that????

No its not capped at 600
It all depends on your gear, and how much +GP materia you put on it.

Iirc, you can get something silly like 706 GP with BIS equipment and max materia melds at the moment. And food, of course.