The Catalyst will use the Cosmic Flux currency that is earned from a wide variety of activities in the game. The costs for the different item slots are:
Bracers and Cloaks: 600
Belts and Boots: 800
Gloves and Shoulders: 1200
Chests, Helms, and Legs: 1500
If a character vendored, disenchanted, or destroyed a Season 3 item that you want to use for this system, please visit the World of Warcraft Item Restorationpage for assistance.
Q: What secondary stats (Haste, Versatility, etc.) will be on the items made by the Creation Catalyst?
A: The tier pieces all have specific secondary stats regardless of what item is put into the system, only the tertiary stats (Leech, Speed, etc.), and sockets carry over.
Unfortunately, if you do not read this, you would assume (as I and many others did) that if the game lets you convert it, it’s letting you make a set piece. This is not the case, it’s letting you convert the piece into part of the transmog set, which is a 9 piece set, and not a tier set which is a 5 piece set; even though the tier set pieces are also part of the transmog set.
Of course, I’ve also got a transmog set where the pieces I’ve got that make it up are 3/9 of one set and 2/9 of the other set even though both sets have the same name – the Sepulcher of the First Ones.
the one other benefit from using the forge on bracer, belt, cloak, & boots is you will change the 2nd stats on the piece to the transmog stats.
So you might have a pair of high ilvl boots with so-so stats, but you could convert them to the transmog piece with your class prefered stats… you will only know by playing around with the forge and seeing how it changes for each individual piece.
Remember also, any socket or tertiary ability (speed/leech/avoidance etc) will be included in the new forged piece.