The Marketplace now has a Market Transaction History as of April 2012. This shows activity of offers, whether buying or selling, in the different areas of the marketplace.
The values of the minerals determine the Mid-Market Rate. This is a mean average of the selling prices and the buying prices of the offers put up by players. Depending on updates and player actions, these values can fluctuate greatly over time. For example, Copper may be lower than the value of Zinc for a week, because players may be offering more of it at a lower price, or Zinc may suddenly start being worth more than Platinum because of an update to how much is needed of either mineral to upgrade a particular item.
VIC days and Pack Credits Edit
VIC days and Pack Credits are gained by spending real-life money to acquire resources in-game. They can be sold to other players through the Marketplace, and generally cost a moderately high price of credits to buy, due to their rarity.
Weapons and Armors Edit
Weapons can be put up for sale in one of two markets, depending on whether they are standard or researched. Armor can also be offered for sale. As opposed to the other areas of the Market, you cannot put up a buying offer. Instead, you can browser through items currently offered by other players and decide if you wish to buy any.