A general warning about buying Bitcoin mining hardware.
Due to the ever-changing difficulty in the code, everybody considering purchasing any kind of ASIC mining hardware, should check out this site first:
In the MINING DASHBOARD, insert your numbers in 'Market & Hardware Parameters'
Type in your Hash-rate, power consumption and how much you consider pay for your new mining rig.
Try to punch in one of the popular 5 GH/sek. miners and you'll see, how strong (difficult) the BTC-code has become.