This is sooo sad...

I did input the data for a RedFury (2.5GH/s at $200). Current exchange rate $737 per bitcoin.
In first month it makes $30, second $15, third $7, so on, for a total production of $58. Net loss $142.
No wonder everyone tries to unload their ASIC miners on ebay! At current hardware prices, in a few of months will be no more money to be made with those.

In order to make some return ($36 for life of device), a 10GH/s miner would have to cost $200.
A 500GH/s would have to cost only $11k in order to generate $905 for life of device. That means that if you pay $12K for it, you are losing money.