No need for an equal trade restriction. You either accept the trade, or you don't. If I want to trade an exotic for a bunch of Spinmetal, it should be my choice to do so, and the other party's choice to accept those terms. Why are the only options for unwanted inventory to discard or dismantle it? Player to player should be an opt-in choice, open to whatever terms are agreed upon by those involved. Player to vendor should be an item sold for an amount of Glimmer set by the vendor, its equivalent value reduced for purposes of economy balance (Rahool takes his cut, or Xur skims off the top, etc.).