I'm honestly really mystified regarding how the economy of the game was designed. It doesn't seem particularly self-sustaining, even for very short periods of time. The best method for making gil as a crafter is to take advantage of other people leveling up crafter classes but ain't got time for that. I'll just hit the general points of curiosity:
1) Gear in general. This stuff is basically worthless. As you level up, you are showered in gear by quests and dungeons. I leveled SMN to 50 and crafted none things for it even though I'm level 50 everything. There was simply no need. Then you hit 50 and have AF, start working on AK gear and DL. Sure, you could get Vanya, but why bother? Just get DL, then Allagan/AF2 stuff, since it's all way better (especially if you don't like vaporizing materia).
2) 2 star gear. This is basically the only stuff that is even possible to be better than everything that is essentially handed to you. However, this stuff quickly runs into either one of two problems: 1) It's too much effort to get as opposed to DL, because it's NOT better than DL on its own, yet costs ridiculous more tomestones to make. 2) Once tomestones are plentiful on your server, the cost of this stuff goes into the gutter anyway. You'll see HQ Vanya Robes being sold for LESS than the AH price of the potash necessary. I suppose meaning people feel the other ingredients are essentially freebies? This is probably exacerbated by the fact that most sane people just get DL then sell extra tomestones afterward, making the supply of potash or whatever super high and the demand exceptionally low (quickly crashing the price of potash and other mix ins, which will never recover because everyone is doing dungeons to get ATP constantly all the time, this will only get worse). If Vanya was easier to get than DL from a tomestone perspective, maybe demand for it would have been higher.
3) Materia. This is basically the only thing that will be sustainable for any period, though the market is basically only for the people who are super into being the best possible prior to Allagan stuff, since it's a total waste unless you're trying to max out HQ Vanya, Gryphonskin, whatever gear. Which is fun, because it basically means crafting itself makes almost no real money over time, unless all you're crafting is stuff to SB with, then I guess running dungeons in your SB gear all the time to get that high grade materia quickly. Or FATE grinding in SB gear in high level areas. Was the intention for materia to be the ONLY market that remained viable for more than a few weeks?
4) Food. I have no idea why most all food is essentially useless. They say people will probably use it more for PvP. Why? In FFXI people used food because it was pretty much essentially, either to do more damage or to hit anything. The best dps food in FFXIV like, gives you slightly more crit rate, which may or may not do much of anything. I guess for tanks food is more of a thing, since VIT is a stat you can actually get on food, but that's like the ONLY primary stat you can get on food. Why is there no STR, DEX, INT, etc. food? If food gave you a substantial edge in content, or content was designed so you needed food, food would be an actual viable sustainable market, but that's totally not the case.
5) Potions. There are some set-ups and whatnot where alchemy stuff can be useful, but generally it's useless like food. I mean, FFXI was not a great MMO, but at least there were reasons to buy food, or potions, or you know, crafted gear. It seems like this game was designed to where you need to buy basically nothing. So why have all this involved crafting and gathering system? So people can figure out that you need to mostly ignore it, other than crafting and melding your relic weapon? Because certainly crafting and melding relic weapons is not a viable market in and of itself.
6) Raid drops. I think it's interesting that essentially no money drops come from any high level raiding content. This seems like yet another missed opportunity to spur on the economy. The only way anything is worth anything is if it's relatively rare, or super desirable but maybe not worth the time of very many people to get it themselves. There needs to be a demand, and a relatively low supply. It feels like every thought was put into making everything super accessible, casual, etc. at the expense of ALL else. Is crafting "just for fun"? Do the designers have some thought on how they would like people to make gil, besides I guess killing monsters and NPCing stuff?
Are things really expected to change with the release of furniture, or PvP? If food doesn't give enough of a boost for anyone to care about in PvE, why would PvP be any different? Is there any thinking behind keeping any particular market sustainable, so crafting anything is worth the time you invest into it? From a PvE standpoint, nearly all crafting is essentially worthless, with so few points of interest that you will have insane competition on anything likely to make even the slightest amount of money. For legacy servers, there may have been a wave where lots of repeatable LQ items were being bought for nice profit, but that's a very short term operation.