公买公卖

buying and selling at fair prices

public / collectively owned / common / international (e.g. high seas, metric system, calendar) / make public / fair / just / Duke, highest of five orders of nobility 五等爵位[wu3 deng3 jue2 wei4] / honorable (gentlemen) / father-in-law / male (animal)

to buy / to purchase

to sell / to betray / to spare no effort / to show off or flaunt