Someone gave me a high offer on some p pots I was selling and was telling me "I merchant prayer potions, both buy and sell." When I got to Edge bank noticed he wasn't there. PM'd me to say he was above the general store. Decided to look (I already decided I wasn't going to trade) and he was actually above the house used for Dragon Slayer quest. He was alching there. I think a huge key is mentioned above. Making sure the would-be trader is a lower combat level so that the would-be lured thinks the person is no threat at all.