The Consignment Houses for Heroes are Wentworth's Fine Consignments, located in Atlas Park, Kings Row, Steel Canyon, and Talos Island. Villains use the Black Market, located in Cap au Diable, Mercy Isle, Sharkhead Isle, and St. Martial.
The Consignment House works across servers. Items being sold from any server, US or EU , may be purchased on any other server. It does not, however, allow trading between Heroes and Villains.
At level 10, you will have the option to run through a training session similar to a story arc that will introduce you to Invention system. You may want to wait until level 12 though since you receive a free IO during the training session and level 12 allows you to receive a level 15 IO. However, a character may begin using the Consignment Houses/Black Market at levels below 10 (provided you can safely get to it). This will allow you to buy and sell items in the event your personal storage and vault storage gets crowded.
The Consignment House uses a secret bid system. Here is the in-game explanation of this system as provided by the Wentworth's Employee in Talos:
The Black Market uses the same secret bid system as Wentworth's.
If multiple players are selling an item for different amounts, the person with the lowest list price will sell first as long as a bid is higher than their list price. Thus, if a lot of people are listing an item for 100 inf, someone who lists the same item for 10,000 inf may never sell it even if people are paying 100,000 inf for it. Likewise, it's possible for someone who lists an item for 100 inf to sell it for 100,000 inf while someone else who lists the item for 10,000 inf only sells it for 10,000 inf.
Each character has a limited number of transaction slots that they may use at the Consignment House. A character starts with one and earns more as they advance in security/threat level (see the Leveling Chart for details). Additional transaction slots may also be earned through badges.
One transaction slot is required for each item put up for sale or for each bid placed. Salvage and recipes may be bought or sold in stacks of up to ten.
The vast majority of items available in the Consignment House are sold by players. However, a a one-use market teleporter, available either as a Consignment House Transporter (for heroes) or a Black Market Transporter (for villains). This temporary power may be purchased at a fixed price of 10,000. The teleporter will transport its user to the Consignment House of his or her choice. The Consignment House has an unlimited supply of this item. A character may not possess more than one of this item at a time, and must wait at least 30 minutes after using one before he can use another (though he may buy another immediately).
There are two sets of fees associated with using the Consignment House. Both fees are applied to the seller, a listing fee and a transaction fee.
Because there are fees associated with selling on the Consignment House, it is possible to lose money, especially when items do not sell.
Notice, though, that you are essentially only charged one fee, since the first fee is taken out of the second if the second actually occurs. If you put an item up for sale and it successfully sells, your overall net profit is 90% of what the buyer paid for it, no matter what minimum price you asked for. (This is technically untrue at the extremely cheap end, where items are priced so low that they sell for less than 50 influence, but the extra charges in these cases are in the low single digits.)
When an item is put up for auction, a fee of 5% of its listed price is charged to the seller. If you do not have enough influence/infamy to cover the fee, you will not be able to list it on the Consignment House.
Note that the minimum fee is 5 inf. If 5% of the list price is less than 5, you will still pay 5.
If your item sells, this amount will be refunded. The amount will not be refunded if the item does not sell, or if you cancel the auction.
When an item sells, a transaction fee of 10% is deducted from the amount it sold for. However, the transaction fee will be reduced by the listing fee, which will be refunded since the item sold.
If a character is inactive (does not log in) for 60 days or more, all items and all influence in the Consignment House will be lost. Nothing is refunded or returned to the character. Logging in a single character will not protect items for other characters on that player's account. Each character must be logged in individually. It appears from player testing that the item loss occurs during the first server maintenance period after the 60 day limit.
Though not an intended use of the consignment house, it is possible to use the consignment house to transfer influence between characters on the same account, cross server. See Influence Transfer for details.
You've sold 50 Inspirations on the Consignment House.
You've sold 50 salvage on the Consignment House.
You've sold 50 Enhancements on the Consignment House.
You've sold 10 items on the Consignment House.
You've sold 50 items on the Consignment House.
You've sold 100 items on the Consignment House.
You've sold 250 items on the Consignment House.
You've sold 500 items on the Consignment House.
You've sold 1000 items on the Consignment House.
You've sold 2000 items on the Consignment House.
You've sold 3000 items on the Consignment House.
You've sold 4000 items on the Consignment House.
You've sold 5000 items on the Consignment House.
You've sold 5000 items on the Consignment House.
You've sold 6000 items on the Consignment House.
You've sold 7000 items on the Consignment House.