What farming means in this game
Gil by the million, tomestones to the weekly cap, mounts sitting behind a drop rate, and the job levels underneath all of it. This page collects the things that are a time problem rather than a skill problem, which in an MMO this old is most of what people buy.
What to buy first, honestly
If you are behind on the story, the story, because it gates everything. If the job is not at the cap, levels. If both are done and the gear is thin, tomestones and savage. Buying in that order costs less than buying the expensive thing and then needing the cheap one anyway.