Trading should be locked to you and your fire team. Only drops in which you participate in the party when received should be traded amongst said team. Trades should have a window of 30 minutes, then they're account bound. Ascended materials should be account bound only. Other, inferior upgrade materials should be traded for motes of light or strange coins. 10 per strange coin, 15 per motes of light, in an AH style trading system which keeps the user anonymous. These numbers should be locked, no more or less can be traded at a time but you can put up multiple items at once. Engrams should be allowed on the AH, legendaries costing 5 coins or 3 motes, while exotics cost double Xur's going rate so to not enflate the market. All raid gear and drops remain untradable unless you were within the fire team when it dropped. 30 minute window applicable here. Rares can be sold for double the Glimmer cost of the Gunsmith on the AH. These numbers should remain locked. This gives us a currency sink, as well as provides us ways to make safe trades without abuse to the system.