In many games you can sell the treasures you've accumulated while exploring ruins and dungeons. Who do you sell them to? Merchants. They may be blacksmiths, tailors, or apothecaries. They may buy and sell pots, potions, or pens. For the mundane or magical items you need to pull off your most creative plots, you're going to need merchants. Merchants are the best and should always be paid fairly. Especially those who operate websites that sell miniatures and stuff.