This isn't nearly as much as it seems. You will get lots of gald from sellable materials and from completing Sub-Plots. By the end of the game you will have more than enough gald to spend.
If you want to gain some quick gald you can also craft some weapons, sell them, and craft them again.
You can also sell valuable items to merchants. These are dropped from enemies so cooking a meal which increases item drop and wearing a Lucky trinket is beneficial. Items can also be farmed from the Training Grounds in Viscint by taking part in the Group Battle (these have a 60 min cooldown).