This is getting really entertaining gamble. At 440 USD/BTC S5 suddenly becomes money making machine. At least for a while 
"Money making machine" with 80% revenue going to maintaince is not even a funny
If you have S5 - sell them ASAP!
Revenue to maintenance is unimportant, price is. I purchased a bunch of S5 at 0.0028 which at 440 usd/btc means almost 2% per day from mining, so I don't plan to sell right now ;-)
Do you need to pay the maintence cost? If you have to, then the Hashnest will turn it off when the difficulty is high.