Buying and Selling Items
To buy or sell items you must first find a vendor. They are usually located in starbases but you might find them elsewhere, including planetary atmospheres or even in space.
Once you locate a vendor, click on their Trade button and you will see the store inventory appear on the right side of your screen. The categories of items available at this vendor are represented with buttons. (If the vendor doesn't have the category of items you want, look around for another vendor. There are often other vendors nearby). Vendors will now react to you based on your reputation/faction. Some vendors may not wish to sell anything to you and will instead ask you to leave.
Your own cargo inventory will be on the left side of your screen. There are two buttons here - Vault and Equip. The Equip button allows you to access your cargo hold and mounting points. The Vault will allow you to store items for safekeeping. Most stations have vaults that you can access, and they all hold your same inventory. In other words, if you leave a laser in your vault at the InfinitiCorp Salvage Yard, it will also be in your vault at New Edinburgh. Note that since you can't dock at an unfriendly station, you can't access your vault there either.
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To view a vendor's merchandise, pick a category from the vendor's window and you will see all the items of that type that are available to buy at this store. Select an item by left-clicking on it. Right-click on an item in the store inventory and you will see that item's attributes.
Some types of items, like missiles, are stackable. This means that you can stack more than one unit of that item in a cargo slot. Remember that your ship's hull also limits how much you can carry by limiting your number of cargo slots. If you wish to sell a stack of items, you will be asked to confirm this sale. If you wish to continue the sale, press YES. If you want to cancel the sale, press NO.
The basic monetary unit in Earth & Beyond is the "credit." Your current credit total is listed in the vendor's window, and on your own character information window. To buy an item from the vendor, left-click it and then left-click the Buy button. If you don't have enough credits to buy the selected item, you won't be allowed to buy it. To sell an item, left-click it in your inventory and left-click the Sell button.
Vendors will warn you if you're about to sell items for a loss. A pop-up menu will appear, asking if you're willing to take significant losses on the sale. If you wish to continue, click YES. Click NO if you want to cancel the trade.
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You can also talk to trade good vendors to get tips on which items are in demand around the galaxy. By delivering such goods to the area that needs them, you can gain Trade experience (and maybe a little profit!). Of course, Tradesmen will have the upper hand because of their negotiating skills, but anyone can get Trade experience by delivering goods that are in demand. (Remember, you have to visit the Trade Goods vendors to get information on current trade routes. Other vendors won't be able to help you.)
Trading with Another Player
To make a secure trade with another player, you must be close enough to exchange items. Target the other player and select the "Trade" button on your targeting interface. Inside starbases, right click the other player, and select "trade" from the popup menu. You will see the Trade interface pop up in the middle of your screen.
If you are giving an item to the other player, drag it from your inventory into the Trade interface, and drop it in the "You Give" box. You can trade up to six items at a time. If you wish to give money to the other player, click on the coin icon and enter the number of credits to exchange.
Now look at the "You Receive" box to see what the other player is offering. You can right-click an item in the trade screen to view its details, just as if it were in your inventory. If their offer is satisfactory to you, click the "Confirm" box. When both players have confirmed the trade, then the items are exchanged from one cargo hold to the other.
You can also get experience by trading experience-eligible items to other players. However, each item that offers Trade experience will only do so the first time it is traded or sold.