Black Market items are purchased in-game, in the Shop/Storage window, under the Black Market tab. Black Market items are purchased the same way as GP items, only using NX Prepaid or NX Other rather than GP.
Under the Black Market tab, you'll find three different categories of NX Cash items:
Special
Character
Gear
Base character changes, Clan resources and other items
Mercenaries for hire
Weapons and equipment vital to your mission
When you purchase an item, it will show up in your Inbox. You must activate an item from your Inbox when you want to use it. The duration for the item won't begin counting down until you activate your item.
Where can you get Nexon Cash? It's easy! You can charge your account with NX by buying and redeeming a Nexon Game Card (available at all 7-11, Blockbuster, CVS, Rite Aid, and other participating stores) or by using Paypal, via the Charge Account link.
For more details on buying items and where to get Nexon Cash, click on the Cash Shop Guide button above. If you're unfamiliar with Nexon's Cash Shop policies, please read the Guide before making purchases.