Enter a town, locate a training room, and saved the game. Create a temporary character. Remove (not delete), one of your regular characters from the party. Add the temporary character to the party. Place the item or weapon to be duplicated into the temporary character's inventory. Remove the temporary character from the party. Add the regular character back into the party. Remove all characters from the party, then reload the saved game. The item or weapon should be in both the original and temporary characters' inventories. Repeat this process to duplicate the item or weapon as many times as needed.
Create one permanent and six temporary characters. Add all six characters to a party and transfer all gold to the permanent character's inventory. Have the permanent character buy any equipment or items. Remove the permanent character from the party. Create and add another permanent character to the party and repeat this process until all permanent characters have the desired gold, items, or weapons.