It costs 0.988 BTC.
Playing with 15% difficulty - stable BTC price.

For now it will do like 5 days of 0.020 = 0.100
Then 2 weeks of 0.017 = 0.238
Then 2 weeks = 0.207
Then 2 weeks = 0.180
Then 2 weeks = 0.155
Then 2 weeks = 0.135
Total after 11 weeks is 1,015 BTC.

Power cost   = 61 kWh/week = 671 kWh. At $0.1/kWh that is $6.71 = 0.011 BTC.
Even at 4 times the power cost, it will be profitable within 11 weeks.

You can continue the calculations - say power costs = $0.40 / kWh. That is 0.088 for 2 weeks.
13 weeks = 0.117
15 weeks = 0.102
17 weeks = 0.088 <- Lifetime at $0.40/kWh
19 weeks = 0.077
21 weeks = 0.067
23 weeks = 0.058
25 weeks = 0.050
27 weeks = 0.044 <- lifetime at $0.20/kWh

The S2 has half the power costs, so will add like 10 weeks lifetime. But not shippinjg before in 3-4 weeks, so make it 6 weeks longer. And it will start earning at higher difficulty lower profits.