Quote Originally Posted by TheTen View Post
Do all your Duty Roulette and Beast Dailies every day, and the Challenge log whenever you can. Only spend gil on repairing. Don't bother with food or materia. (You don't need any of it until you decide to do serious Coil/Extreme Primals.) If you aren't crafting yourself, sell all your crafting materials that drop from monsters on the marketboard. When your Mythology Tombstones are full and you don't need them for gear, buy crafting mats with them (they are under Other) and sell them on the marketboard (remember to check the price history).

You will make a lot of gil that way without having to grind or play the market.

And do ventures, while often you get scrap, sometimes you get Savage Aim Materia IV, which sells ~500k a pop on Balmung.