1. Bartering and Haggling
The prices generated here are listed as standard "book" prices, adjusted slightly for the merchant's tier. However, merchants shouldn't always accept face value. Let your players roll Persuasion or Deception to secure a 10-15% discount. Conversely, if the merchant dislikes the party, they might mark prices up dramatically. Remember that in an average fantasy world, a single gold piece represents a significant amount of wealth for a commoner.