https://blogfreely.net/fishcor....d1/do-you-know-how-t
The Item Upgrader in World of Warcraft The War Within introduced Valorstones, and Harbinger Crests as two currencies to upgrade equipment. These can be exchanged at the NPCs for upgrading items, Cuzolth and Vaskarn. Each item may be upgraded up to its maximum level only once for one slot. Upgrades to that slot are then cheaper following. The pity system, introduced with The War Within, also lowers the extreme upgrade variance. Upgrades Upgrades are elements that boost performance or add new functions