I find that very hard to believe. You're trying to say he was making nearly 20mil per day since the game's release? I'd be surprised if anyone anywhere has capped gil yet, but it seems likely some will by the end of the year.
And anyway, if you want to control the market on any given item you can do that with 10mil or less. All that having a lot of gil gives you is the power to buy expensive +3 items. But the people with the most gil aren't the ones buying these, they're the ones making them.