I have a few metal 30 rounders that I don't use, and I'm thinking about trying to sell/trade them at the gun show this weekend. All three look similar with black followers. One is Labelle, one Parsons Precision, and one Sanchez Ent on the floorplate. What should I ask for them? $10 each, 3 for $25? Trade 3 for 2 PMAGs?