http://www.gmx.net/themen/spiele/akt...ay-aufgetaucht
Unfortunatly it's in German, but let my summarize it for you.
A guy is selling FF2 for 50.000$. It is that expensive, because it was never released as a module in an english version. This module was created solely for the 1991 Consumer Electronics Show in Las Vegas and is therefore the only legal copy. It was abandoned, because the developers wanted to focus on the new 16 bit console: SNES.