The word "stench" refers to a bad smell. This describes the Ammonites as something unpleasant and unwanted. AT: "realized that they had become repulsive to David" or "realized that they had angered David" (See: [[rc://en/ta/man/translate/figs-metaphor]])
It is not clear if the Ammonites paid the entire thousand talents to the king of Maacah, or if they paid him only a portion of that amount and gave the rest to the other cities that sent additional chariots and horsemen.