With using the market, its not a matter of gil coming into the economy, but taking it out via taxes while only money is exchanging hands. It is not generating gil. Your wealth goes up while another goes down. Also, even with the cumulative gil from FATEs and Leves and such, you also have to look at individual generation. You could have 500,000 gil come into the economy in moments, but if players only made 200 ea. then it won't really matter. But I guess you're not educated enough to understand or care as long as your own pockets are lined.

If people do not generate gil on an individual level to both cover their costs and earn a positive income, the prices shall eventually deflate as those buying your product will eventually not have enough gil to purchase your product. You will have to lower your prices often in order to sell. I can chalk up a small scale example if need be.