Badass Rank Farming
To build a high Badass Rank, and gain all the perks associated with it, create a
pair of new characters in co-op mode and have player 1 beat player 2 in 50
duels. This gives 166 Badass Ranks. Save and quit, then start another new game,
creating another new character for player 1 (don't bother messing with player
2's character). Fight another 50 duels, with player 1 winning them all for 166
more Badass Ranks. Repeat as desired, and delete the pile of unwanted characters
when you're done.. If you set the controller configuration to something where
you can just keep tapping the melee-attack button without ruining your aim at
the other player, you can finish a duel-run like this in roughly 10 minutes.
Thus, over the course of one hour, you can build up 996 Badass Ranks.
Place the desired item(s) on a character, and ready or create a second character
to take on as many of the item as you wish. Start a two-player co-op game with
the first character as player 1 (and the other character as player 2,
obviously). Give desired item(s) to player 2 and have player 2 save and leave
game. Quit game from PS3 system menu. Because the game doesn't save player 1
when player 2 leaves, nor when you quit from the system menu, now both players
have said item(s). Repeat as desired (for faster duplication, transfer all
copies of the item to player one, save-and-quit with both, and start over with
the duplicates on player 1).