There are programs that can open PSF format, you know. Just search for them. I think some of them can also export it to mp3s, I'm not sure. But if you don't want PSF no matter what, here is an almost-copy of another post of mine:
They have it with the Final Fantasy mp3s at
http://www.ffshrine.org/media.php. However, they don't actually have the files for download on the Web. That just tells you how to use IRC to get them. If you're on a Mac and using Conversation (http://www.macupdate.com/info.php/id/12666) to connect to IRC, I can help set it up, but otherwise you have the tutorial on that page to go on. Note what the channel topic tells you: type !list instead of /ctcp acpobot triggers. However, at the moment, two of the bots meant to supply mp3s have got their triggers messed up and nonfunctional (HerpBot and SyphBot), and they are the ones with the OST, so if you have the same problem, you might be out of luck. (I hope I'm not the only one this is happening to. In the triggers, they call themselves erpBot and yphBot, and adding the missing H or S does nothing. Anyone?)