(a) Discrimination in price by a distributor between customers that purchase milk, cream or any dairy product of like grade and quality, under like conditions of service, is prohibited if the effect of such discrimination may be substantially to lessen competition or to injure or destroy or prevent competition with the person that either grants or knowingly receives the benefit of such price discrimination.

(b) The establishment of price schedules by a distributor which offer to any customer special prices or services which are not offered to all customers purchasing any milk, cream, or dairy product of like quantity, under like terms and conditions, within the same area is prohibited.

(c) Discrimination in price by a wholesale customer between consumers that purchase milk, cream or any dairy product of like grade and quality, under like conditions of service, is prohibited if the effect of such discrimination may be substantially to lessen, injure, destroy or prevent competition with the wholesale customer that grants such price discrimination, or substantially to produce competitive detriment to consumers who are not afforded the benefit of such price discrimination.

(d) A distributor who is not a processor, purchasing processed milk from a distributor that is a processor, whether such milk is packaged under the label of the selling distributor or the label of the purchasing distributor, shall not, except for the purpose of meeting a lawful competitive price or lawful competitive condition, offer or establish lower wholesale prices for such milk than those offered or established by the selling distributor, if the effect of the price differences may be substantially to lessen competition or tend to create a monopoly, or to injure, destroy, or prevent competition with any person who either grants or knowingly receives the benefit of them.

(e) Proof of any sale of, or offer or agreement to sell, milk, cream, or any dairy product, by a distributor at less than the prices offered to other like customers subject to the provisions of Chapter 1, Part 3, Division 21 of the Code and these regulations, or offer by such distributor to sell any other product in combination with any dairy product at less than cost, establishes a rebuttable presumption of a violation of said Chapter 1 and these regulations. This presumption is a presumption affecting the burden of producing evidence. Offers or agreements to sell, as used in this section, include offers, or agreements to sell which are conditional, or for which price schedules will be established at a future date.