My version of the Final Fantasy X OST is from about 2005 and pretty low-quality. Does anyone have a version of the FFX soundtrack in good old high bitrate MP3?

I suggest you to try and ask a re-up here: Thread 109301

I've an old personal rip of my copy, but it's encoded at 320kbps constant bitrate (the one which was uploaded in the thread linked above pretty much gives you the same quality while taking up less space).