To use the Black Market Auction House, you have to open the Trade Office and click on the fourth tab.
On the first loading, you will not be able to see much and you will need to gather 10000 Coins to unlock the Auction permanently.
Coins
Coins can be gathered through various options in the game and can also be collected through the normal trade panel.
The Bidding
Bidding will start instance wide.
You will see the specific and sometimes rare item and everyone on your instance can bid on it.
The bidding will be with random currencies (Gems, Eventcurrency, Ressources, etc.) and you have to pay the full visible amount.
The value increase for the next bidder will increase in predefined steps from the last bid.
Everyone can bid until the last second and only the last visible/system-displayed bidder will receive the item.
This will offer a wider variety for you to receive rare items, but only 1 player on the server can actually obtain them.
If you do not win:
If you're not the winner you will receive your bidding back. Any resources used to bid will be automatically returned to your storage. In case your storage is full or the returned amount exceeds the available storage, the remainder of the resource will be sent to the star menu.
If you win:
The auction winner will receive a notification mail once the auction is over. The auctioned item will be added directly to your storage in case of resources. In the case your storage is full or the resource amount exceeds the available storage, the remainder of the resource will be sent to the star menu. All other items, such as buffs, specialists, and buildings will be added to the Star Menu.
System behaviour:
When another player outbids the current highest bidder, the outbid player will receive a notification and a system message in chat.
The timing in which offers will be started is random and there is no fixed setup of what items will be offered.
If no bidding is active, it will display a small note to "wait and come back later". The bidding will not run non-stop.