Sorry for the delayed response. In short, yes.
Longer answer: So FFXIV servers are designed for about 5000 simultaneous users, though perhaps large ones have a bit more. But only a small fraction of these are market participants, which is a tiny number of people for a market system. So even on big servers most markets are not terribly stable, barring a few very high volume ones. But on some of the really small servers the sellers will remorselessly ra--erm, take advantage of you. But big servers, there's at least more than 1 seller, and if the prices get too high other sellers will step in and put downward pressure on the price.
The disadvantage is new items can be very expensive due to a larger amount of gil in circulation. This mostly happens when new items are introduced in a patch, but if you don't mind waiting, the price always drops as the market develops and matures (i.e. some things that were millions can go for 10k now). Truly limited items--only real estate at the moment--will be disproportionate expensive (and in the case of several servers, utterly unavailable), however. Housing is currently, for the most part, just fluff, but SE has said they're developing more uses for it and currently have no plans to add more real estate on high population servers.
Lastly--in this game, you can pretty much ignore the market. You can get raid-ready gear all from token drops and as drops from said raid (best-in-slot pieces being a mix of both). Crafted gear is always a tier behind... Although some top-end players still prefer it for the flexibility the materia system offers, and this is where things can get expensive. But once more, generally the 'best'/most powerful gear is unsellable/nontradeable, earned from tokens and drops.
And preemptively, if you want to join a very large server, the small hours of the morning (6amish) are the best time to do it. Don't use the server list on the Lodestone; instead look at the in game one, which updates every 2 or 3 minutes.
Good luck!