Players can place commodities (wood, oil, any of the 5 ores) up for sale at their market. Only 1 item can be on sale at a given time. Friends can then visit a market to purchase the item available, up to the quantity specified by the seller. This is at 200 coins per ore, or 20 coins per wood or oil unit. One can get either a scarce ore type, or something they need immediately, while the seller stands to make roughly twice the cost (or more) of the item being sold.