Yeah, hunts and quests in general are the main money source. Also sell treasures/monsters' loot too and keep maybe 2-3 of each or so of you want to craft spells, except the quest-related ones in the list below and the Rare Coins and Debased items, which you can use for easy EXP farming by making Expericast spells with them:
- Metal Scrap
- Rusted Bits
- Dynamo
- Magitek Core
- Glass Gemstone
- Earth Gemstone
- Sky Gemstone
- Magnetron
- Monster Claw
- Cylinder
- Coreurl Whiskers
- Barbed Scythe
- Cactuar Needle
- Spiked Armor
- Sturdy Helixhorn
- Repair Kit
Btw, I don't know how well communicated it is in the game, but you can accept 10 hunts at once from any tipster and then select whichever you like as the active one in the hunt menu at any point. Crazy thing is, this was only patched in almost a year after release and we only could do one hunt at once back then, meaning you had tons of loading screens when fast-travelling between tipster and hunt, then back to the tipster again to do the next hunt, rinse and repeat. You guys playing this game now are lucky, lol.
Also, yeah, the combat can often get very chaotic.