OP covered it in the last section under "Gold Spammers". Essentially loot farmers and a shady black market will find a way to circumvent any restrictions. Once you let that monster loose, there is no good way to control it, unless you kill it for good. I did hear one decent argument where the rules were: - limit it to items only - limit it to items of the same type/rank (exotic arm for exotic arm for example - so trading is always a zero sum game) - no glimmer in trades (op covered this...but really glimmer is useless after level 10 so its a minor point) - only allow it between players on the same fire team, and [i]only[/i] in the post game lobby after a raid or crucible match. (Farmers are less likely to actually complete a real portion of the game with you to make a sale - they probably still would though if you were offering them real cash) This would be very difficult to make happen, and would likely be called a "nerfed" or "half-assed" trading system...drawing more criticism that it is worth to implement. From there it's basically "Buy your way to Legend".