While not exactly the most physically useful craftsperson who first comes to mind, the Financier is nonetheless indispensable for keeping things running in an organization. Handling the books, handling funds, and making arrangements and deals, as well as handling investment strategies all without bothering the rest of the organization.
People love payday, and they never like being told that they can’t do something just because they don’t have the money for it.
Financiers can be extremely shrewd and cautious, but a loyal one can keep adventurers in the black, and can handle their fortunes well, so that when they need that new suit of custom-built armor to handle a crazily-specific demon – They have the funds to do so. They manage, they invest, and they often act as an intermediary to the bank for the adventurers.
As well, because of their gold-glittering eyes, they often come across paying jobs that adventurers may not have noticed, or may not even have able to become aware of, because such a task was strictly within the purview of the Financier’s more well-to-do social circles.