Since you're not selling it, do you know what things in particular you're looking for for it? It's in
much better condition than the FF:MQ I've got and would love to trade for it, but don't have anything "extra" at the moment. If you provide a list, I can see what I can find around for you and pick something up for the trade.
(Also, MQ tends to be one of the least valuable FF games in my experience, so almost ANY sealed copy of any other FF is likely to be a big price difference -- unless we're talking FFX-2 or another PS2 or more-recent one?) (Edit: Also, only talking about NTSC formats since I never looked for non-NA final fantasy games)