Hey guys, saw a lot of comments, so I will try to address one by one.
75C working temp - I don't see anything wrong with it. S9 can withstand 90C and above from what I have researched and talked with other fellow forum members. We used them in an office AC-ed room, so pretty much we had to accept our surroundings. I didn't invest in any
additional cooling or so. If I had to add more AC of fans, electricity bills would have been horrible.
Statistics - approximately for the period 1st February - 1st October 2018, both machines have mined 0.40782123 BTC All Times Reward (I am copy/pasting from Slush Dashboard).
Photos, I am adding here.
https://www.screencast.com/t/llRG2g5ISYychttps://www.screencast.com/t/JulEqiFRhttps://www.screencast.com/t/b2YXWjQKahttps://www.screencast.com/t/B7KRgogcDtPrice - i really have no idea, how much would used S9's (13.5 TH by specifics) fairly be sold for at the moment according to you guys? I am looking at Bitmain site now and the prices for new ones are ridiculous (of course there are customs taxes, waiting time etc)