Get the iPad. A lot of colleges have full on desktops or iMacs running OS X to running Windows. My college has iMacs everywhere, you literally can walk into the A Building on campus and like 10-12 iMacs you can use to do work. In class in particular, a tablet can be used for digital textbooks, and any relevant class materials. For example, I buy most of my books on Kindle, so I can have a lighter workload devoid of carrying books. I currently am still shopping around for a tablet, but if I need to I can pull up my entire History book on my phone.
A tablet would not only be good for books, it would be good for putting down assignments and calender events, and reminders and have them synced to your phone. Touch screen interface is so much easier for navigation than unfolding and typing up what you need to do as well. But this all is dependent on you getting out of your pj's and going somewhere to do your work. Then again, with a Bluetooth keyboard, you can type up your essays in Microsoft word or Apples iWork suite.
I would put it like this, if your school has long library hours with open access to desktop computers, then get the iPad, if your school doesn't get a Macbook Air 11. But on that same vein, some students encounter problems running certain software for classes, for example macbooks aren't the best for stuff like Myitlab as office sill hasn't been updated for Mac OS X.
In your case, since you mentioned funds, I would get the iPad. Safest bet and you can get a keyboard case or bluetooth case anywhere to do some work if you want or need to.