Yeah I did that trick too but waited for Ch. 2.

Reason why is because in Chapter 2 you can go to Guadosalam and talk to the Inn Keeper and he'll give you some good info. If you find the lady that will give you over *0,000 gil it would be easier to pay off O'aka's debt. (Note I added the "*" because you can have different amounts depending who you talk to). I advice you save before you do this.

I eventually stopped at over 1 million gil. I was a Gillionaire!