-At the start of the game when you get to the tutorial with the first shopkeeper, buy from him, and purchase the Paladin Tunic. The price of the tunic should be 0 gold and the selling price will be 1 gold. You can keeppurchasing and selling it as long as desired. Note: this was done with version 1.18.6718, using a Monk.
-When talking to Aribeth for the first time, keep asking her about the Recall Stone. Each time you ask her, you will get 100 gold.
-Note: This trick requires the most recent patch for the game, but not without the Shadows Of Underintide expansion pack. Play a multi-player game long enough to get some expensive armor, swords, gems, etc. Have whoever is running the server save the game, then save your character on your client. After that, drop all your armor, helmets, weapons, gold pieces, gems, etc., basically leaving you with absolutely nothing. Exit the game but leave the server playing, then reconnect with your previously saved character with all the items you dropped still in your inventory. All of your items should be in the floor. Pick them up and sell them. You can repeat this as many times as desired. For the person who is running the server to do this, save the character and game before dropping the items. Now drop everything and exit out. Reload the map with the saved character that still has everything then go in and pick up the items.