Mass. Gen. Laws ch. 138, § 25A: Discrimination in prices and discounts prohibited

Section 25A. No licensee authorized under this chapter to sell alcoholic beverages to wholesalers or retailers shall—

(a) Discriminate, directly or indirectly, in price, in discounts for time of payment or in discounts on quantity of merchandise sold, between one wholesaler and another wholesaler, or between one retailer and another retailer purchasing alcoholic beverages bearing the same brand or trade name and of like age and quality;

All price lists or price quotations made to a licensee by a wholesaler shall remain in effect for at least thirty days after the establishment of such price list or quotation. Any sale by a wholesaler of any alcoholic beverages at prices lower than the price reflected in such price list or quotation within such thirty day period shall constitute price discrimination under this section.