Following are a number of back-translations as well as a sample translation for translators of Proverbs 20:14:

• Kupsabiny: “A person who buys something beats down (the price) saying, ‘You! Go away, this one is not good,’
  or/but when he has bought, he boasts about it.” (Source: Kupsabiny Back Translation)
• Newari: “The buyer bargains saying,
  "This is too expensive, this is too expensive!"
  As soon as he turns to go
  he brags about the good deal he got.” (Source: Newari Back Translation)
• Hiligaynon: “A buyer under-estimate/belittles the sale so-that he can-bargain. But if he has-bought already, he no long under-estimate/belittle (it), but-rather he even boasts/brags-about (it).” (Source: Hiligaynon Back Translation)
• Kankanaey: “The one-who-buys, he complains-about the price of what he buys, but when he leaves, he boasts-about his skill in bargaining.” (Source: Kankanaey Back Translation)
• English: “People look at things that they are about to buy, and in order to get it for a lower price sometimes they say, ‘It is no good/It is poor quality,’
  but after they buy it, they go and boast about having bought it for a cheap price.” (Source: Translation for Translators)