The blacksmith in Murky Waters does not live alone, nor is he the only merchant. He and his wife have a son who also trades in weapons, armor and related products as part of the family business. The boy does not seem really into doing it, but he has to obey his father's wishes, apparently "or else!". The lad can be found next to the his father's shop, looking forlorn. Like most teenagers, he seems to get up relatively late as well.
His attitude toward being a merchant is quite ironic as his inventory is easily the most lucrative in the entire game. Not only is he the first merchant who sells the mighty Perun runestone, which is the most powerful temporary weapon augmentation in the game, but he is also the only one who sells Gwalhir, which is the 2nd best steel sword in the game.