No person engaged in commerce or food commerce, or both, in the course of such commerce, shall pay, grant, receive or accept anything of value as a commission, brokerage or other compensation, or any allowance or discount in lieu thereof, except for services rendered in connection with the sale or purchase of goods, wares, service, or output of a service trade, or merchandise. In all such transactions of sale and purchase, neither party to the transaction shall pay or grant anything of value as a commission, brokerage or other compensation, or any allowance or discount in lieu thereof, to the other party to the transaction or to any agent, representative or other intermediary therein, where such agent, representative or other intermediary is acting for or in behalf of or is subject to the direct or indirect control of the other party to the transaction.