Craft furniture. Sell materia. Do Ishgard restoration turn-ins to farm skybuilder scrips, then buy mounts/dye/drip to sell on the marketboard. Play a tank so you always get the adventurer in need bonus for roulettes. I'm sitting on 133M gil and I'm not even trying to make it. There's a zillion options.how do you earn that much money?
If you do craft, gather your own materials. You knock out achievements, you level up, and your materials only cost you time.