By completing stikes or some story missions, sometimes you get a Strange Coin.You can use this as a currency for buying exotic gear and other upgrades from the Agent of the Nine. But that guy appears only from Friday through Sunday and he is located in the room where the Crucible Quartermaster and the Crucible Handler are ( the hall before you enter the room where all the Class Vanguards are). You need to farm some coins to buy his gear BUT all he sells is exotic. You can also but exotic engrams with Motes of Light but i'm sure what this things are yet, maybe similar currency like the Coins. That being said..... anyone want to farm Strange Coins?? :P Add me on 360 GT: GormitarasGR *UPDATE* When you reach max lvl (20) , you can still earn xp and every time you accumulate enough to 'lvl up' you earn get a Mote of Light.