You can duplicate items early and a very easy way early in the game. First off you must have at least one of the items you want to duplicate. Example would be a High Potion. Now go to the very first save point in the game. Its on Leons right as he enters the castle. Now before you actually go to the save point you really just need to go to the hall where the save point is. If you walk on the left side of the screen on the red part of the carpet you should see a green part of the floor where it looks like the moon is shining through green. You need to stand on the red part of the carpet facing the window on the green spot of the floor. Next press start and go to items. Scroll down to the item you want to duplicate. You should notice that all of your items are going up by one. You can get a max of 9 in normal mode and 5 in Crazy mode doing this. You can do this for any item. Try it with a gem like a diamond then sell the diamonds back to get infinte money.