So, I don't know if anyone is looking for ways to get gold, but here's are methods that worked for me:
Low Levels: If you are still based in Stornway or Zere, or places like that, this method is for you. Just outside and east of stornway is a pach were coagulants spawn. Also, south of stornway there is a fisticup spawn point. Pick these up, and you'll quickley get a some good gold.
Mid Levels: Wormwood creek, places like that, use platinum and mythril ore. Platinum you can find north-east of Bloomingdal, and mythrill north-east of batsureg. Money gaining at this point is somewhat pointless, since the best gear is gained through alchemy.
High Level/post game: This is where it gets fun. First off, don't bother with gem slimes, or gem jamborees. The method I use is faster, and gets almost as much gold as a gem slime per battle. Okay, so go to a grotto, realm of the mighty, or cringle coast in the north, and find some night Knights. You'll need a theif that knows half-inch, and if you can get the acclaim among theives thats even better. So once you find the Night Knights, keep half-inching until you get a dark shield or a skull helm. Dark Shields get you 8600 gold, which is almost as much as a gem slime. Skull helms get you slightly more, but you don't get those as often. Keep getting drak shields until you have around ten, the on the way back to the bank in stornway, stop a batsureg and tower of Nod to get mythril ore. Then go to stornway and sell the dark shields and mythril ores.
I hope this helped anyone looking for ways to get gold. If you have any other ways, post them in comments. Thanks for reading!!