Lying is generally considered a bad thing to do and when someone lies about the prices of the items they are selling it is likely to make people angry because they feel like they are being cheated
Consider the statement "At a shop a seller was lying about the prices of the items that he was selling.". Based on this "The fact that the seller blatantly lied about the prices of the items he was selling made me so angry" a true statement? Yes, no, or I don't know?