I just crafted a full set of Silent Legion (each piece to be sold separately)
I place the items in my Trader Thralls (sales) Inventory and place my Thrall just inside of my protected gate.
Players on the server by either word of mouth or forum support are informed that I have a Trader Thrall located at my Highlands base.
Someone approaches my Thrall and accesses something similar to what the merchants do in the Neutral City, except there would be a much more in depth UI Window for browsing items, with a purchase price listed with each item…
The player decides to buy my Silent Legion Helm for 1k Bark… the player selects the item and clicks purchase. If the player has 1k Bark in his inventory the bark will be removed and placed into the Thralls inventory and the Helm would be transferred into the players Inventory.
This could be done several ways, it could be like a crafting station, where you would see the bar build for, lets say 5 seconds. Giving the player the option to back out of the deal and would help with a smooth transfer process.