Personally i think if you are totally upfront that what you are selling is in fact fake i have no problem with it.    What upsets me is when there is nothing to indicate that what you are buying is not the real deal.  Or when they use selling points that relate to the "real" label,  such as worn by celebrities or pictured in such and such magazine.   If you are going to sell a fake admit its a fake and show pictures of the actual item so that a buyer can actually see what they are getting.