The 7th Saga/The Wizard Rune

Cave of Baron
Before adventuring in the following dungeon, you should better know that afterwards some items will be permanently missing from all shops. It's not a glitch, it's part of the plot (but no spoilers here). Therefore, stock up nine of each of the following: The other, less important items that will be missing are: bottles of fossil, shield destroyers, magic siphons, bottles of ice, bottles of fire, vacuums.
 * 9 Bottles of protection (the Star Rune will change effect as well)
 * 9 Wind balls (the Wind Rune will change effect, too)
 * 9 Exigates
 * 9 Magic herbs 1 (9x20 = 180 MP, that can be useful)
 * 9 Potions 1 (9x40 = 360 HP, that can be useful)

BOSS: Monmo
Monmo is weak against Fire spells.