(I feel 10 pounds lighter)
Get rid of some of the gil dumps.
I'm not business major but anyone can see the markets have too much supply not enough demand.
Take away a lot of these vendor items that players can make. Replace the weapons vendors in various parts of the game for example with market boards. It will still say "Weapon Vendor" but for instance....
Your in a level 30 zone, talk to a merchant, he will only allow you to BUY level 30-ish items from the market.
Also a lot of gathering mats should be taken away from the vendors too. Why destroy gil? The point is to circulate it throughout the community. Sure, some gil dumps are needed. Not when the smallest houses are 7 million gil though.
Honestly I have no problem with the big giant gil dumps. Like housing, and if you feel there is too much gil, add some more. Like some uber expensive armor or something.