...
3) 4BTC? 5 S1's cost ~4.96BTC, have less chips and no PSU. This ain't a charity.
...
It still has to be a valid purchase though, the S1's made that and returned ROI reasonably quickly @6
BTC ROI will be 9-10 months away.
Slush's pool just added 220TH here the last couple of days and dropped my return per block down by 20%. With more power being added, 9-10 months away is generous and in scheme of things is way too long.