Ark. Code Ann. § 4-75-806

The payment or allowance of rebates, refunds, commissions, or discounts, whether in the form of money or otherwise, or the extending to certain purchasers of special services or privileges not extended to all purchasers purchasing upon like terms and conditions, or the offering of a combined price for fresh milk or any fresh milk product with another commodity or service which is less than the aggregate of the prices for which the milk or milk products and other commodity or service is offered for sale, shall be considered costs of doing business in each separate sale or transaction, and each separate sale or transaction must stand the test of cost plus four percent (4%) as provided in § 4-75-805.