okay 1 s-3 = .66 btc factory direct from bitmaintech.
Takes 5 to 7 days to arrive.
So lets say it shows on Aug 15th.
Or direct from you.
cost is 479 in btc that is .81 btc
If you host up time is under 1 day. and a psu is not needed.
So your 479 = .81 btc is not more costly then bitmaintech's 391 usd .66 btc
Since faster mining of at least 4 or 5 days is about .05 or .06 btc and a psu is about .1 btc
your hosting fee is 135 if you pay for 3 months
that means If I buy 1 for 479 + 135 = 614 for 90 days of mining
here is a breakdown of roi at 91 days and 8% diff jumps along with btc at 584