challenged as these examples show to tell the difference between the real and authentic item except when you begin to use a product, there's a significant quality difference. >> reporter: the best way to avoid counterfeits may be to follow an old piece of advice: >> probably the best giveaway is if the price is too good to be true, or you're probably buying a fake. >> reporter: so you all hear about the fakes, gregg, and the fact you can buy them on line, for example, maybe several thousand dollars you buy for $50. the magic bullet, beats by dr. dre, only 10% off online, you think you're getting a good deal when actually they're completely fake, and then inspectors and agents found these, these are jeanses like some sort of generic jean. upon inspection, they were fake true religion. they'd actually put the fake label over the top, and so the real label that would have been used when they got to a store was under.