Everyone here is debating the issue on combating RMT and stabilizing the markets, be it for or against reducing the gil made by sparks, people seems to think there is some simple solution
The solution is actually more complex, but easily achievable. But put succinctly - we have to collar the markets. THat is literally the only way to control RMT in a game like this. Let me explain:
The problem here is that the Bots have more than enough accounts to take advantage of the lower cap by sheer numbers of accounts. You might lower the top end rate of gil made via Sparks by some minor amount, but that does not prevent them from using alternative means through advantage of numbers to control markets.
Say you employ a system that limits you to capping out your sparks once a week, and exchanging that amount. What prevents them from then cycling out characters or accounts from making those sparks and preserving their workflow?
Meanwhile, we also have a player issue - the people who purchase and play multiple accounts to play - while a pillar of support for the life of the game, are also inadvertantly hurting it by crashing or inflating certain prices in ranges and acessbilities they were not designed to be - preventing those items from being adjusted appropriately. However, neither of these would be a major issue if there wasn't so much gil to throw around that a Million seems like nothing.
The issue here isn't that there's too much gil being added into circulation, it's that there's not enough going out. Prices for rare crafted items and materials are in the multiple millions, and the costs for making SU5s and other in-demand items are in the tens to hundreds of millions. That's not a reasonable rate for most casual players in the game, (not without a huge source RMT will take advantage of) and those are the ones returning that you're aiming to preserve. - but all that gil is just going into the banks of Gilsellers or other players who have more than they'll ever need. This makes gil less valuable and more inflated.
So rather than just making gil less accessible, give gil some sort of high-end-game value to be spent at NPC - something similar in usage to say a potpourri, that permits purchases from NPC many high value items on the auction house. Then give a stable, but limited, method of making gil independent of the open market. (Sparks can remain this method if it is capped like SE intends.)
Meanwhile, at the same time, turning in similar items of high value may also grant this currency but at a slightly lesservalue than trading in raw gil equivalent to the purchase of that item, so that high value items can be traded for - in case the market is over-flooded with said items. This guarantees a minimum value of the items - giving a stable range of variance that allows players to determine what an item is worth between a set minimum and maximum.
This effectively hard stabilizes market, preventing willful inflation or deflation of certain items of the game. Both gilsellers and players who exploit the system will be prevented from cornering or the markets, and the developers will be able to properly gauge and adjust the value of items in the game to keep them both desirable and balanced for the whole base.
This also insures Gil and items will both have a stable value in the game with enough leeway between to allow for a range of choice. Both the buyer and the seller benefits from an exchange somewhere in the middle price range and it's the playerbase that decies where within that middle ground the true value of the item lies - preserving at least a part of the idea of the free market.
Gilsellers will have no grounds to stand on because they can't inflate the prices of items past the maximum point. And legit players will still have reason to farm for the items because they will get access to at least the minimum value, which is (if done correctly) a lot higher than the way for earning raw gil. The game would remain healthy, players retain a sense of choice (if limited) and RMT gets murdered in cold coin.
Hey... I guess we can call the currency you exchange valuables and gil for "Cold Coins", if SE wants the idea.
Anyways, this is one professional System's Analyst's idea on how to resolve the RMT issue. Whehter or not it gets liked, or utilized, I'll leave in your hands. Either way, a part of me stubbornly loves the game and I'll continue to try to survive in it.
Have a good one!