Trading would ruin the market of teh game in general. Everyone will be just camping farm spots (since its broken anyway) and never play the actual game. All Bungie has to do is make it so normal lower level mobs drop greens for farming upgrade mats. Higher mobs (20's and armored mobs) should have a higher drop rate of blues with possible chance of legendaries. And actual Strike bosses (22-28) should be the ones dropping high level blues, purples and chance of exotics. If people were to be able to trade it would just make new users sheeple who go to people for gear right away instead of actually earning their own gear.