The Black Market is the auction house of the GTM server. The Black Market can be found on GTM1, in between the Weapon and Armor Shop in the alleyway.
(A picture of the Black Market on GTM1)
When you first open the Black Market you are shown two options Browse (The Bookshelf) and My Offers (The Book and Quill) from these two you can browse through the Black Market and even list your own items for sale
(An Image of the Browse and My Offers GUI)
Inside this GUI you can go into the My Offers, where you can see the offers you have auctioned and spaces where you can Buy or Sell items. You have up to 7 of these spaces.
(A picture of the My Offers GUI)
Once you click on one of the Empty Slot you come up with the customize your offer with the 5 items.
These items are used to Customize your offer. These are
Changes the item you are requesting or listing
Change Offer Type
Changes your offer from Buy or Sell
Changes the quantity of the item
Change Price (Each)
Lets you customize the price of each item
Creates the offer and lists it on the Black Market
(An image of the Create Offer GUI)
Now moving to Categories, this menu can be accessed by right-clicking the Browse button. Once you click this button you can browse by 6 categories. These 6 categories and the items put into these categories are...
Kwon's Booty Shorts
Samurai's Air Jordans
All Weapon Skins
All Player Heads
Misc / Others
1 Casino Chip
10 Casino Chip
50 Casino Chip
100 Casino Chip
300 Casino Chip
800 Casino Chip
(Here is an image of the Categories GUI)
After all your items of the same slot have been bought or after the time you put it up for has finished, all your money now gets auto claimed, and you now have full grasp of your earnings. If your items have not sold, then they will also be returned to your inventory. Your items will only claim well at spawn. As well as you cannot sell weapons in the Black Market with weapon skins on them, and you cannot sell armor that does not have full durability.