A promoted weapon is relatively difficult to get to craft, you need several days or gold to get the necessary, when a mob to drop you a weapon, armor or accessory risen and this has the stats you want is like having nothing.
I therefore propose that somehow they can change these stats in a way that is affordable. For example having a piece of heavy equipment with healing power, strength, power, but it is not what you want, as you put it to the mystic forge along with 5 vials of powerful blood, one Deldrimor steel ingot and 2 globs of ectopasm and so get a weapon of berserker
Ie the material put determines the type of stats you want, and the material promoted the type of weapon or armor (excetuando rolls damask, these should not be used because of its high cost, it would be unfair) else are the weapon you want to change and glob of ectoplasm that are common.