I don't know if there are any fakes but on amazon there was this one guy was selling them for around that price new and half that for refurbished ones. I bought one of the refurbished ones off of him maybe a month and a half ago and they were legit. Name was something like adgtron. Maybe it is the same guy.
Hmm i have found some fakes only on DIYTRADE.com and they seem to be using stock photos so I cannot compare the IE6 sold there and the ones that are being sold more cheaply. this is the seller i am referring to http://tipidpc.com/viewitem.php?iid=3034072 He has solid feedbacks and good reputation on selling IEM that are cheaper than retail prices. but the only thing that put me off is that he sells them without any packaging. and on the side note, are there any guide on how to spot a fake IE6 or even a fake CX 400-II because on my search around google, I was only able to find guides on CX300-II, CX400 and CX500. Thanks!
Being that there are fakes for IE7s and IE8s, I would assume there are fakes for IE6s.
For that price, I doubt they're fake. Amazon.com is selling them for $100 right now and being that their an authorized dealer, I'd recommend picking them up from there-- great price and you have a valid manufacturer's warranty.