isnt it a free market? you cant ban people for setting up expensive trades. you can claim its scam and it prolly is but you cant prove it nor request a ban for it. its not his faul if people are stupid/naive enough to accept his trades.
if you wanna see what real scam is, play eve online. people are scammed for millions and billions every single day and its been like this since day 1, 2003. admins and mods completely ignore it.
i kinda like scammers. they create a sort of naturel selection