Best bang for your time investment is Torigoth, south of the plaza. It's always A/A/B and you can run to the trader/salvage supplier. Once you unlock gold cylinders and get Gormott to 5 stars (pretty easy) you can buy them for 5k a piece and use them there; like ten or so will get you in excess of 100k.
Have you been staying at inns and leveling up using your quest EXP? If it's been a while you could get several levels per character.
Still haven't beaten it, made it to the island whose name starts with L (can't remember which one that is) and I keep getting killed by some of the monsters in the tunnel. I could take the left path instead, since they explicitly say it's safer, but I made it pretty far on the right side and now I don't wanna. Though I might have to just to finally progress in the damn story.