Hello,

I have found larger quantity of used S9s 13.5TH/S for 436‬USD (inc. shipping) per miner.

Does it worth buying them, I have free electricity up to 960kWh.

Also there is a problem, there are used s9s .. ROI per unit it's 4.6 months with the current profit. Can one used S9s works 24/7 for minimum of 5 months?