I'm not saying it is right or ethical, but it depends on the quality and condition of the item, plus any shipping involved to get an item to the buyer...If I'm selling something to a stranger, I want as much as I can get...If I'm selling to a friend or acquaintance, then it's 20% less than new, plus the cost of shipping...
Just found out that the wife of a pawn shop owner in a town 25 miles away from my home town works in the local Walmart...When they get ammo in the store, she calls her husband, he shows up and buys all they will sell him (they do limit some items) and then lists it on Gun Broker at an inflated price...
Complaints have been filed with little results on the part of the manager...