I think shouldnt exist marketplace, there should be trade to player-player, you can ask in world chat for exemple: I need this or buy this or that and the seller or the buyer go to the localitation of the seller/buyer, that will made a good ambient on the player's made them socials, etc...search an item on marketplace made feels something empty.
It's about the convience of buying/selling items, people don't want to waste time spamming chat to sell/buy things, then meeting up with the player to complete the trade.