An Unusual Team Captain with the Sunbeams particle effect. One of the most rare and valuable hats in TF2. The value can exceed $1500 USD
Market
Item trading is the backbone of the economy in Team Fortress 2. Weapons, hats, and metal are all traded frequently and have their own individual values. Weapons and hats will be given to the player via the drop system, which ends up dropping a random item about once every hour of playtime. Drops are individual to each player and go straight into your backpack. Better items will have smaller drop rates; hats in particular are rarely dropped via the drop system. Some players have played over one hundred hours without ever receiving a hat this way.
Items can also be obtained via the crafting system. There are specific recipes for almost every item, but more often than not, you can trade for an item for much cheaper than you can craft it.
Currency
If trading is the backbone of the economy, currency is its lifeblood. Since you can't directly trade money to other players, the Mann-Conomy needed something else in order to weigh prices. Metal is the most basic currency in Team Fortress 2. Metal can be crafted by combining two weapons yielded by the same class. For example, the Pyro's Backburner and Flare Gun can be combined into one scrap metal.Keys, which can only be obtained by either buying them from the store or trading, are the next "tier" of currency. Bill's Hat is the next tier, given to those who pre-ordered Left 4 Dead 2. Earbuds, or "buds," are next, and were introduced when TF2 came to Macs. Finally, there's Max's Severed Head, which is rarely used as currency due to its rarity.