I open CEX.io and find this rather confusing price:
GHS/BTC = 0.00747 which is the equivalent to THS/BTC = 7.47 = 4.487 USD
So you need to pay more than 7 BTC for one TH/s? It does not make sense at all. Here's why:
Currently one TH/s generates BTC 1.12 per month = 667 USD.
Don't forget maintenance. One TH/s costs 260 USD per month, reducing the profit to 407 USD, so it takes 11 months to break even. With difficulty increases it will surely never happen.
Am I right?
CEX.io is overpriced and its well kown fact for techies. But for people desperate to invest in mining this is the only option and hence they are gambling. For instance, I know one blonde, who is in r/GirlsGoneBitcoin and earning from private shows, investing whatever she's earning into CEX.io for a mirracle to happen that will eventually pay her mortgage.