Call of Gods features Auction Houses which let you buy and sell items for Gold. To find an Auction House, headover to your race's main city (Sdaq for the Elves, Saintyanley for the Humans and Sodoma for the Undead) and click on the Auction House.
The "Browse" page allows you to purchase items that other player have put up for auction. Items are divided into different categories and there is also a search function.
The "My Consignment" page allows you to auction your items. Choose an item from your inventory on the right and click on it to put it up for auction. Input the price of your item in the "Consignment Price" field and select a "Consignment Time", which is how long your item will be available for purchase. There will be a "Consignment Fee" depending on the duration of your Consignment Time. Click "Confirm" to move your item to the Auction House. If your item is purchased by another player, Gold will be automatically transferred to your account. You can remove your item from the Auction House by clicking on the "Cancel" button.