agape: okay here's my suggestion.. using marketplace to trade items is a dangerous way.. someone might buy the item u wanted to trade.. i suggest u add an option that will allow us to choose a specific user to buy the item we put on mp.. for example.. i want to sell my stamina pot to Player1, i will put that stam pot on mp for 100k buy it now price and it must have a restriction for other players to buy, that potion is intended for Player1 only.. In that case no one can buy that stam pot except of Player1..

try this option..

Public - All players are free to buy
Clan - Only Clan members can buy
Class- Name a specific class to buy..
Player - Name a Player that can buy that item..