doesn't really increase costs that much. Lost Odyssey got a LOT of negative press about the 4-disc requirement, and by only shipping on three discs they technically are small enough for someone with a 20gb hard drive to install all three (you can't, because there's only around 13gb useable on the 20gb hard drives, but the numbers look good for dumb people). four discs - particularly since that'd mean that the videos were compressed less - pushes you to an install size nearing 24gb, which physically restricts you to the bastard 60gb systems and elites.
DVD9 can technically hold 8.4gb, but the read speed lowers once you get farther and farther out along the edge. simple math, that - think of a bike wheel. the disc would have to spin faster in order to read the edges of the disc. most games stripe useless stuff out there, like the NXE install info and really long (and, in turn, buffered) cutscenes. those generally are the cutscenes that looked worse than others.
crystal tools was made to be multiplatform for the specific purpose of bringing all of the FF games made on this generation of consoles to each system if they so chose. the engine is the reason that we didn't see FFXIII in early 2008, to be honest. i'm surprised anyone still thinks that any of these games WON'T be multiplatform. it's not like sony's paying them to keep it console-specific, like what MS is doing with Mass Effect.