Gearing out crafters is the typical money sink if/when you start that. Otherwise it’s saving for a house and or buying the top end crafted gear.I'm at 3 million gil and I haven't done shit. I've sold like 10 things from quests on the market, but that's it. I've probably spent around 300,000 on items as well, probably closer to 500,000 actually. I haven't even finished the first quest from Stormblood.
You gain substantial amounts of cash just playing normally and tossing shit on the mb, sending out retainers, etc.