@1referee
I have to say I was not aware of the crucial importance of a mining pool in the whole process till now

@steamtyme
The maintenance fee is deducted from the daily payout in BTC.
But in the contract they are counting the maintenance fee in USD.
That one for me seems right,I did not went into it,but everyday it is a smaller amount.
I think because the BTC price is getting higher.
I did checked on your link (I appreciate it,big thx:)which you kindly provided the calculator and meanwhile the calculator is forecasting 3,2
On the cloud mining site my forecast is 2,6 at the moment(it was originally 3,2)