https://notes.io/w3Q6L
World of Warcraft Item Upgrades Item upgrades can be used to increase the stats of an item. Depending on the upgrade type it could raise an item's Mark level or Rarity and boost additional stats. Each item has a track to upgrade it. Each upgrade increases the cost of the following one by a set amount. Item Level The value of an item's stats base increase when it is upgraded. The value is the sum of all of an item's leveled-up perks (attack magic attack and defense). Upgrading items can be expensive, depending on the upgrader and the type of upgrade you choose to