Here is a guide for Super Easy money making in Adventure Quest.
First, you can't make super good money at a really low level.
So get up to at the least 65-70 before going for tons of cash.
The first way to get easy $ is to go to Fairwind Springs with your best party, and keep clicking the Stone in the middle of the lake. You will sometimes get a fight, where you will on occasion get a treasure cheat, hoard, that kind of thing.
The second way to get easy $ is to go to Loslosia, the port city, that was destroyed, and get the flower and go talk to sailor Boon. He will give you a map to buried treasure. Just follow the path, and you will eventually come upon a vast treasure, sometimes with over 4000 gold in it.
Hope this helps!