Regular playstation games are no longer in production, and FFIX was the "newest" of Final Fantasys in that vein to be made. Naturally, that should mean there's more of them out there, but...then again, when the PS2 caught the public like a wild fire, it's just not lucrative to mass-produce any of those games. I'd love to say its more rare and higher-priced because it's simply better than FFVIII or FFVII (and it is ), but it's probably like that for an amalgam of reasons.