In clearing out some inventory, I sold my alumen (of which I had a couple of full stacks). I NPC'd a lot of stuff I judged had no chance in the Merchant Wards, but, looking at the current sellers and sale history for the alumen, I went with a sell price of 140, which is almost twice what the NPC will give you. I sold out in about a day. This was on Trabia. You won't get rich on that, but it was nice chunk of change for stuff that was just cluttering up my inventory.