Here is a real spoiler if you have the old version of FF3.

Goto Zozo and have edgar,strago,terra and relm in your party.
Cast vanish on gabbledak then tell relm to sketch them the game should glitch up and escape the battle. Then look in your inventory you should have almost everyitem in the game and over 99 the quanity by them will be 0. Save first though becuase your game could freeze.