more expensive. and this one is the less expensive. >> reporter: sadly, no. >> they look the same to me. >> reporter: exactly the same? >> are they the same? >> reporter: no. that pair, $82. that pair, $24. >> unreal. >> reporter: the inexpensive pants were undetectable to the average observer's eye. except for one subset of the population other teenaged girls. >> those are $82. those are $24. >> i agree. >> reporter: it's amazing like they have expensive leggings esp. and a few people that really know about clothing. are you in the fashion business? >> i am. >> reporter: the fabric matters? >> yes. washes well. it doesn't peel. comfortable on. doesn't shrink. >> reporter: sure enough, the expensive pair is made of nylon and spandex. the less expensive pair is made of polyester and spandex. this has nothing do with durability over time. becky worley, abc news, oakland,