Completely different units. This unit has a dedicated AES accelerator, the FPGA does far less job (allegedly) and is far less versatile than a real FPGA.
You wont mine neoscrypt or any other algorithm with it hence the price difference (or you might mine none if in the end it was a scam)

From an old response when the thread was young :

--What chip, or even brand are you using?
It is not Xilinx/Altera. Spartan-III  can get 1.3-1.5 kh/s, it's true. But most part of the resources will be spent on AES implementation.