Forum:How do I duplicate items on 360 using split sceen?

I just got my Borderlands rental and am level 5 in Fyrestone doing the bandit quest to kill the 8 spying on Fyrestone. I only have xbox Live Silver because I don't want to pay Microsoft for Gold when it should be free like PC and PS3. I heard that you could duplicate with two controllers in split screen on the one xbox but can't figure out how to get it to work. The IGN directions were to start split screen and player one would default to my character, then push start on second controller and select character where I would have the option to select my same main character. I could then give items from player 2 to my main char, exit and when started back in single player my char would have the extra items. When I go to select character for player 2 however it doesn't give the option to select my main character. I have an xbox Live Silver account for my main character and created a second profile for my second controller but the second profile is only an offline profile, not a live profile. Since I can't do multiplayer without gold it seemed simpler to just do offline profile for controller 2. I am looking to duplicate so that I can sell items to machines/vendors to get money because since I can't trade with others I assume I will need a lot of money to buy and upgrade equipment that I can't find from random drops. I am renting the game so don't have much time to keep reloading to go back to open all chests again and again to get little amounts of money.I would really appreciate any help anyone can give me.