Infinite Money for Dungeon Lords v1.0:
Go to the Warrior's Guild in Arindale with some scrolls on you. If you sell 1 scroll while having more than 1 in your possession, the amount of scrolls you have remains the same.

Infinite Money for Dungeon Lords, All Versions:
Use an Elf character, have over 2000 gold, and go to Arindale. Go to the Weapons Shop and select "Treasures". Say that you will pay 2000 gold for the sword and then close the dialog box and open it up again. Click the new option that comes up underneath "Trade" to recieve 500 gold for returning the Elven Sword of Flames. This option will remain, so click away! You may do this trick anytime since you can borrow the sword at any time.