The Kobolds’ New Ringleader is a quest offered by guard Jung in the harbor. After accepting the quest you will enter Bonebites hideout right in the alley next to guard Jung. The quest is classified as long but it is rather quick, especially if you’re about level two. Doing the quest on elite will give you the best rewards but any of the difficulty tiers will give you good rewards.
The reason why this quest is good for making money is because there are a lot of chests and most importantly a ton of collectible items that you can sell on the auction house