hasnest which one is best s7 or s9 for cloud mining?

I do wanna to invest here as looks the only legit and where i can sell the hash to achieve roi, something like 10 months is what the most people says.

Soo my question now is i do see s7 market costing around 5000 satoshis for each ghs, and the s9 is at 14000 satoshis at the moment.

Fees grom s7 is $0.4450 and s9 is $0.2100

I can buy currently 3 x more hash if i do invest with s7 then s9, but the fees from s9 is less then half, soo what you people advice, because i dont know which one is the best and i do wanna to invest.
I do see a huge volume at s7 while s9 has lower volume as well, im curious about the experience you guys have, and please just reply if you are member of hashnet and has experience as well.

I made a test and i had bought s7 hash for 4862 satoshis, and i had sold it for 5005 satoshis, sometime ago, as i know the fee is 0,15%, i had invested 0,0050btc on those time, but instead of i have some profit i had lost 10k satoshis can anyone explain those to me.

From my calculations 0,15% fee from those 500k satoshis would be 75 satoshis? Kindly correct me if im wrong because my balance shows as this -0.00xxxxx this means i had made profit or the website .

Since i had researched and didnt find anything about this im making this thread to get help and understand the result.