Selling an item dupe, it does not involve trading, nor any arena fights.
It has worked for me for every single time i've tried, but i've only copied level 20 blues as that's the only thing i got atm, with no gold :P
Recap:
This only Dupes BoE, BoU items(Item's that binds upon using/equipping).
I've not got it to work with gold yet, and i highly doubt its possible.
I'm selling this for gold(we're talking about huge amounts of gold), or somewhat around 500 Euro.
I'm quite sure that i'm one of a handful people who know about this dupe.
PM me if you want more info on how to purchase it.