Oh my god, you can make SO much gil on Palamecia... (SPOILER)We're just grinding to get those credit chips everyone carries to really upgrade the weapons high. There's a corridor that you can just run back and forth on between save spots and it's golden. Make a little under 8,000 gil each time.
I just found that spot and it's awesome - just repeating the same four battles. The battles take a little time, but they're easy and you make a bunch of gil and CP per battle.