In this case, independent wholesalers of 5-Hour Energy sued the caffeinated drinks manufacturer for selling the product to Costco at lower price than it charged the independents. The manufacturer also reimbursed Costco for its promoting the product every other month or so by offering it to Costco members at a reduced rate. The district court did not abuse its discretion in instructing the jury on the need for proof that defendant sold the same product to Costco when it was also selling to plaintiffs at less favorable prices–even if the plaintiffs had offered compelling evidence on that issue (on which they bore the burden of proof). Also, the district court did not abuse its discretion in instructing the jury on functional discounts. The functional discount theory negates the competitive injury element of the plaintiff’s claim. However, the district court erred in not enjoining defendant under 15 USC 13(d) because under that section the functional discount theory was not an obstacle, The jury did not clearly find that Costco was not a competitor of the independent wholesalers, and the evidence chowed that over 90% of Costco’s sales of the drink were to mom-and-pop retailers, not directly to consumers.