Sorry I didn't follow up on my initial post...switching over to a new computer the past few days.
As a 2nd semester senior in college right now, I can honestly say that out of all the things I own, I value my headphones the most. A good set of closed cans is absolutely invaluable in a college setting, especially the first few years if you live in a dorm. Dorm life is noisy enough without trying to drown out someone else's stereo with your own. In fact, out of all the people I know that had a stereo in the dorms, only one used his reguarly, and almost everyone used headphones.
Unfortunately I can't comment ont he DAC topic (since I don't have a whole lot of experience with them myself), but I think if you want bang for your buck, go with the PA2V2. I have one and use it regularly with my DT770/80s, and I like the bass-y sound a lot (with most music).
Back a page or so ago someone mentioned desktops being too bulky for college life- I would disagree with this, but on one condition. If you have a desktop, make sure to get an LCD monitor, the CRT monitors just take up far too much desk space. If you have a desktop you can easily keep it on the floor next to your desk and still have plenty of desk space to work with. Also, if you do much gaming you will probably want the desktop anyway. If you think you will need the portability of a laptop you can always build a pretty nice desktop for around $1000 (assuming you are comfortable assembling your own computer) and get a cheap Dell laptop...I was able to convince my parents to pay for that when I went off to college since it would have cost 2000+ for just a decent desktop from Dell or the like.
Sorry to get a little off topic here, but just thought I'd put in my $0.02.