The scary thing is when counterfeit products enter the legitimate supply chain. (like those bogus GFCIs)
I agree you may not be able to tell the difference between real Cat 5 and bogus Cat 5 with any certainly but I bet the bogus stuff won't look and feel right if you are used to the real thing. (much like counterfeit money).
I agree you are certainly spinning the wheel when you get a "bargain" from a non-traditional source. It is likely either a knock off or stolen.
