I returned to the starting town with the Mithril key item. This allowed the weapon shop to start selling better weapons. Unfortunately I can't afford even a single silver sword. It turns out all those attempts to up my mana (by using Ming-Wu's mana burn spell) have left me essentially broke. On the plus side I do have a pretty significant amount of health and mana now and I'm about to lose Ming-Wu so no more power leveling until I can afford to buy Faze or Swap myself. Time to plow through the plot!