First question to ask is do you already have a DAW. If it is Logic 8, then you might not need Logic 9 if you can get something else. IMHO its not that big a difference.
I have been using both Logic and Pro Tools for quite some time now and they are really two different pieces of software to me. For music composition, it is hands down Logic for me. MIDI is better(Pro Tools is catching up on this), freeze tracks is crucial for big compositions, performance is slightly better with virtual instruments, and multi-timbral instruments like Kontakt makes so much more sense in Logic than Pro Tools. Bouncing multiple tracks for a mixdown is a dream in Logic but a nightmare in Pro Tools. Real time bounce in Pro Tools just doesn't help with bouncing all your MIDI tracks to audio.
Pro Tools on the other hand is king in audio editing and processing. Having multiple Audiosuites open are great for sound design, audio editing is easier to do precise edits, hotkeys are amazing(crucial for being a serious sound editor), OMF import and syncing to video is simpler. Basically, its a powerhouse for post-production. The plugins that come with Pro Tools isn't as comprehensive as Logic especially when it comes to instruments but the audio processing stuff are good. You will need to supplement it with some third party plugins eventually like a convolution reverb, doppler, etc. But only if you need them. Logic too doesn't come with everything.
If you already have Logic 8, just go ahead and get Pro Tools 10. With the education discount and 4 years of upgrades, its the best version of Pro Tools ever. The iLok will be justified once you start getting into buying more plugins as the big names like SoundToys, SPL, EastWest, etc also use it. Having an iLok isn't that bad when compared to the days of carrying an MBox around.
If you are just looking around for another DAW, do take a look at Reaper. I like it for working with MIDI, it comes with an amazing set of plugins and it really cheap. It better suited to music composition and music mixing rather than post production sound. But I like it because it is extremely lightweight but extremely flexible.