World of Warcraft - item upgrades Upgrading
The item upgrade lets players boost an item upgrader kit's gear rating up 700 points, and then give it a bonus. Items can be upgraded by having them in inventory before heading to the kiln.
Certain items are worth upgrading because of their unique stats. (For instance the perfect broken point armor that is rolled can be used in melee PvP). Other items like weapons aren't changed much after an upgrade and therefore aren't worth the cost.
Weapons
Upgrades to weapons can boost their numerical stats, such as attack damage, crit chance and PvE/PvP damage. Weapons also come with a flat bonus that increases the damage they deal per second. A lot of weapons also come with an unaffected bonus that is activated when three or more identical weapons are equipped in a group. This bonus could exceed the damage that an upgrade item alone can do.
The cost of item upgrading a weapon depends on its rarity and current level.