You can refer to the above image for a step by step guide on how trade via Auction House for Neverwinter Online Astral Diamond purchase:
Step 1: Locate the nearest auction house. Please prepare any item with quantity equal to each million of diamond purchased. (e.g. If you are buying 30 million diamond, you will need to prepare 30 of the same item)
Step 2: Post each item amounted to 1.12 million. Note that there is an incurred of 10% tax for each item sold. Therefore, you will be receiving 1 million diamond for each item sold.
10% tax will be imposed if you use the gateway or talk to the in-game NPC to access the Auction House.
12.5% tax will be imposed if you use the icon to access the Auction House from anywhere else in-game. This is a convenience charge.
Step 3: Our Seller will be searching for the item posted in the Auction House based on the provided delivery information. It is important to ensure that your character name and item name example: “playername@handle(Item Name)“updated is 100% accurate.
***We suggest buyers to put Potion as consignment so that suppliers are able to find the item easily and complete the trade smoothly.
Step 4: You will receive an alert ingame once our sellers has ‘delivered’ your order by purchasing your auction. You will also be notified via email as well. Take note that partial delivery might occurred and it’s best to check the status of your order the amount of delivery made.
Important: The guide is only for Neverwinter Online Astral Diamond purchases.