A gold sink is any game mechanic that removes currency from an in-game economy, thereby counteracting the inflationary effects of farming. Without gold sinks, in-game prices would spiral out of control, rendering it impossible for new and casual players to afford to trade with those that play frequently.
Some players also use gold sink incorrectly to refer to items that trade among players at prices far exceeding their functional values. However, player-to-player trades never remove money from a game. In fact, gold sinks are designed to prevent such unreasonable prices for all but the most highly coveted items.
 Guild Wars gold sinks
The primary currency sinks in Guild Wars are the NPCs who require payment for goods or services: the crafters, rune traders, and others who take gold or materials from players, permanently removing it from circulation. The most important sinks are:
- Chaos Gloves — one pair costs 10 , 75 and 250 .
- Destroyer weapons — each one removes 5 , 10, 10, and 250.
- Guild Halls — fully stocked, each one sinks 510 .
- Obsidian Armor — each four-piece set removes 60 , 105, and 105.
- Skill Hunter — this title can cost up to 290 to buy 290 Signets of Capture.
- Treasure Hunter — completing this title requires the purchase of upwards of 4000 worth of keys and/or lockpicks (after discounting the merchant value of most of the contents).
- Vabbian Armor — a four-piece set costs 20 , 14, 14, and various other materials.
- Lucky and Unlucky — requires spending significant amount of cash on Lockpicks, Nine Rings, and/or Rings of Fortune.
- The three consumable-based titles (Drunkard, Sweet Tooth, and Party Animal) are ineffective sinks, since players typically acquire them from sources other than merchants.
- Although the purchase of consets removes value from the game, their importance in speed farming increases the value of their component materials, counteracting the anti-inflationary importance of a true sink. If all conset (and similar items) were removed from the game, it is possible that prices for some materials would drop.
- Similarly, the Zaishen Chest removes the Zaishen Keys (a gold substitute) from the game. However, Zaishen Keys by themselves have no in-game value; only the items removed from the chest can be sold to NPCs.
- The Hall of Monuments and the related HoM calculator are the two most important sink-related incentives, since the expectation of rewards in Guild Wars 2 encourages people to transfer cash and goods to NPCs. However, their existence also causes people to farm, which creates new wealth.
- Gold sink on Wikipedia