Here a buyer is criticizing what someone is selling to get a low price from him. After he buys he boasts about the good price that he pursuaded the seller to give him. The full meaning of this can be made clear. Alternate translation: "'Bad! Bad!' says the buyer criticizing the seller's wares, but after he buys he goes away he boasting about the low price that he paid" (See: [[rc://en/ta/man/translate/figs-explicit]])