As of 20 may 2017, the auction house is implemented

You can go to auction house at
Trowulan gate N and go to 88,49

How to sell :
Place item on the NPC, and select your time of bidding
1 day = 1% of bid price as tax
2 day = 3% of bid price as tax
3 day = 5% of bid price as tax
(I recommend 1 day) for now you cannot take / cancel the item you already place on bid until the bidding time is over or someone take it instantly which is 2x the price you put.

How to buy :
You can browse the NPC for the items and you can place your bidding price, there is a minimum amount of bid each time you want to raise the bid.
If you price is the highest bid until the end of bidding time, you can get the item.
You can also buy the item instantly without having to wait the bidding time to be over.
But it will cost you 2x from the starting price.



Good luck!
-WillOfD-