Lululemon alleges that Costco is selling "infringing versions" of its clothes through the private-label Kirkland brand, among others. Lululemon is claiming Costco is selling knockoffs of its leggings, according to a lawsuit the company filed against the popular warehouse chain. In the 49-page lawsuit, which was filed in the U.S. District Court for the Central District of California, Lululemon alleges that Costco is selling "knockoff, infringing versions" of its clothes. Lululemon leggings can run over $80 for a pair of yoga pants, while Costco's are closer to $20. "Indeed, one of the purposes of selling 'dupes' is to confuse consumers at the point-of-sale and/or observers post-sale into believing that the 'dupes' are Plaintiffs' authentic products when they are not," the lawsuit alleges, per CBS.