My friend has 3 HK 5.56 x 45 mags for an AR and is wanting to sell them, I am trying to find a fair price but can only find new ones on the net (for $50 new) so I am trying to figure out what a fair price to give him is. Does anyone know how much these would go for used? There is typical wear on the finish from being used and one has a small dent, but it loads up just fine. The dent is on the right, rear corner about 2 inches up from the bottom. Thanks for any help!