acquisition prices are tolerated. Every precedent in the field makes clear that the interaction of competitive forces, not price-rigging, is what will benefit consumers. Id.; see also Mandeville, 334 U.S. at 235, 68 S.Ct. 996. Similar reasoning applies here. Highmark’s improperly motivated exercise of monopsony power, like the collusive exercise of oligopsony power by the cheese makers in Knevelbaard, was anti-competitive and cannot be defended on the sole ground that it enabled Highmark to set lower premiums on its insurance plans. Having concluded that paying West Penn artificially depressed reimbursement rates was an anticompetitive aspect of the alleged conspiracy, it follows that the underpayments constitute an antitrust injury. See Atl. Richfield, 495 U.S. at 334, 110 S.Ct. 1884 (<HOLDING>); Brunswick, 429 U.S. at 489, 97 S.Ct. 690;
holding that injury to broker through loss of commission was not antitrust injury holding that a plaintiff must show antitrust injury in order to bring an antitrust lawsuit holding district court erred by incorporating issue of anticompetitive market effect into its standing analysis confusing antitrust injury with an element of a claim under section 1 of the sherman act and stating district courts approach may have been result of the similar antitrust injury label applied to injury component of antitrust standing analysis and to marketplace harm element under section 1 holding that an antitrust injury is an injury that is attributable to an anticompetitive aspect of the practice under scrutiny holding that an antitrust injury is a necessary element of a  2 claim