Begin a 2 player game and give all of the gold to one of the characters and save the game for
the same character.
Begin another game with the saved character in 2 player mode and repeat the process.
Do this as many times as you wish.
You can duplicate a belt item by dropping 9 items on the ground ( creating a 3 by 3 square ) . While standing on the center item you just dropped, pick the item you wish to duplicate and press the X button. Then press the triangle button. Now what happens is that the original item stays in the belt, and a duplicate item is dropped to the ground. remember that this only works with belt items.