How do I access the cave shop?

The cave shop is ONLY available between certain levels in the Misty Ruins. The bags of coins you find in Misty Ruins can ONLY be spent in the cave shop, so be sure to spend them whenever you see it, before continuing, because the thief can steal cave tokens but he does NOT appear to steal your items. There are wizards every few levels that also can resurrect the most powerful 'resting' hero. You can buy health potions and resurrection bottles, but these cave artifacts are ONLY available between battles. The arrows are also useful for dealing 25% damage to enemies on a level, but ONLY the enemies that are showing, so expose as many as you can before using them.