t's also available directly for sale from Bitmain, and will actually make you some money after the halving, but not enough to roi. If you're loking for ROI, try the S9.
I find this statement of not being able to ROI not entirely truthful. If your electricity is good, which I think you have already done the math on because you're interested in mining, then it should be .07 or around there. Yes the difficulty will rise from s9 and that is more efficient, the s7 should still be able to ROI depending on price and difficulty after the halving.