(Phrasal verb) to offer a great bargain; to give away or sell something at a low cost in order to attract business; to offer people huge benefits or do special favours for others; a huge disposal of goods at reduced prices; a huge markdown sale
Definitions (粵典–words.hk)
語句
平賣到半賣半送嘅地步 to sell something cheaply; to sell off something at giveaway prices; literally: to sell big bun