To find the items you are looking for, just click through the various categories in the Item Mall. Be sure to check out our special offers and promotions. They often contain rare items which will help you progress in the game. By the way: You can see how many Black Gold Coin you have available under "Balance" at the top.
To buy an item, just click on the "Purchase" button for that item. If you would like to purchase more than one of the same item AFTER PURCHASE, THE ITEM WILL BE SENT FROM THE SHOP TO YOUR INGAME PREMIUM INVENTORY
The item will be credited to your account after it has been purchased. Assign the item to a character in order to use it in the game. You can find the items you purchased from the shop in your premium inventory.