I will not have to pay for electricity so I don't care about efficiency,all I care is about how much TH/S I could get for a cheap price.
I was thinkin about : http://hashra.com/moonrakerwarp3/ , but i've heard not so good things about HASHRA, + this is a pre-order, I would like something from stock.
If you say that blindly you're making a mistake. You can buy ancient BFL and Avalon gear and even S1s for less than current hardware costs. The problem would be that they would exhaust so much heat you would need to expend money cooling solutions.
What you mean to say is for new hardware with <1.5W/GH/s, who is the cheapest.