The United States Supreme Court has held that, unless a seller can be found liable for granting illegal discriminatory prices, a buyer cannot be held liable for inducing or receiving such prices.
Great Atlantic & Pacific Tea Co. v. Federal Trade Commission, 99 S. Ct. 925 (1979).
Michael J. Hennessy,
Antitrust - Robinson-Patman Act - Section 2(f) Buyer Liability,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol18/iss1/15