Investing into building mining rigs can still bring you some profit IF you have cheap electricity, around 5-6 cents per kwh. Anyone above that is big risk and I would not touch it.
What do you mean "building mining rigs"? Do you mean building and reselling GPU miners - quite clear that it is not feasible for ASIC
I think he means buy the ASIC and mine. If your electricity is just 5c per kWh, that will be quite profitable.