I dont understand the reason to buy this (and others like it).

I can can get 2 TH right now on CEX.io for that price can't I?  Is my math wrong:

1.2 TH unit (1.6 TH in turbo which probably draws more power) = 8499.

So:

8499/$500 = 16.998 BTC

Current CEX.io price of .0085/gh so: 16.998/.0085 = 1999 GH

And if you use pbmining: 16.998/.0056 = 3035 GH..

It just doesnt make sense to me.  Am i missing something?

And if i am not..  Here is a link to where you can get 3 TH immediately for the price of the 1.2 TH unit:
http://pbmining.com?ref=robocoder

Disclaimer, this is my referral URL - please use if i just gave you a way to get more than twice the hashpower with no preorder.  All my money goes to ARF anyway..