Thanks for the help!!
I have decided not to use these gpus xfx, I will finally try to buy sapphire, msi or gigabyte that are gpus that I know.
Probably what I would save by buying xfx would later lose it with heat problems
Nvidia cards is the best option if you want to mine other altcoins compared to AMD cards that only few coins that you can mine.
Try RTX series RTX 2060 or check the gtx1660 ti which is one of the best options nowadays. Base on profit.
If he goes out and buys a second hand RX 470 8GB for like $75 he will make about $0.25 per day prior to electrical cost and with 10 cent power its more like a loss of $0.04. If he goes out and buys a new RTX 2060 for $350 his profit will be about $0.45 per day and with 10 cent power it will be like $0.14 profit.
So which one makes more sense? I haven't really looked into the 2nd hand price for the RTX 2060 but I am assuming it won't be too far off from the new price since its still a fairly new GPU. Even with free electricity he is better off just gettin the RX 470.
Unless the alt coin market bounces back there really isn't much out there to mine profitably anymore.