10 month ROI isn't guaranteed because market can crash in coming months, if that happens your ROI will take longer to accomplish, can be up to 13months or even more, my advice is you need to be prepared for any possible out comes
ofcourse, for sure !
The way i look at it, and i hope he does too, is its an investment, and a gamble .. hence, dont put money in that you cant lose, and dont expect , count on, or depend on, the return...
Also consider we are heading into winter and it might cost some (like me) the same amount of money a day to turn on electric storage heating than it does to run a rig and use that heat instead of paying for just heat so if you can calculate your ROI with free heating included its win win. Those with gas or larger houses might not have the benefit or rather the outright free heating just subsidized heating in part so if you can place the rig in a place that keeps a floor warm and turn off the radiators on that floor might be able to cut the heating bill rather than remove it outright.