Congrats on Harvard. It's an exciting place, and clearly you can handle the work, but do be prepared for an atmosphere of continual social one-upmanship. (So, hey, it's just like high school
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I would suggest you split your budget and get a pair of highly isolating IEMs, plus a pair of "beater" headphones that you can pull on when you don't feel like using IEMs and that you won't feel like you have to watch every second.
School can be a loud, rowdy place, and high-isolation IEMs will feel like your 'secret weapon' on those nights when you don't feel like going out and hunting (sometimes at length) for a quiet spot in the library. In fact they're your secret weapon when you're in the classroom waiting for a test to start and want to spend those last minutes cramming instead of being distracted by everybody around you. Or when your roommate has brought home a date and you kinda need to not hear for a while. And all kinds of other situations that happen in school. Seriously, get some IEMs.
For the IEMs I have in mind something like the Etymotic ER-6i, Jays D-Jays or S-Jays, or Shure SE110. You can read up on all of these and make a best guess about which one will best suit you (the Shures may be the most durable of these, and that's a factor not to overlook).
For the beater headphone I have in mind something like the Sennheiser HD201 or Panasonic RP-HTX7: inexpensive, closed so they won't bother people nearby, and not really theft targets. The HD201 is cheaper, the HTX7 a little easier to drive and has a shorter cable that's more convenient in some situations.
On your budget you won't get both a superb IEM and a superb headphone. But even budget IEMs are remarkably good these days, so I don't think you'll be suffering either.