Im just about to setup my first mining rig 5x Rx580 8gb, Gigabyte H110 Mobo.
I am fortunate enough to not have to pay for electricity where I live, so would it be ok for me to buy a cheap PSU even if it is super inefficient? or would it risk damaging my components?
Just looking to keep spending to a minimum without compromising anything!
thanks
Efficiency is not the only reason quality PSUs are preferred. You're also considering expected failure rates, how "clean" the output DC power is, and warranty services.
For consumer PSUs, those with the guts made by Seasonic, SuperFlower, or FSP would be my first choice.