It looks like the only thng Microsoft Home & Student has that Office Pro doesn't is One Note. HELLO-O! You can take notes in Word.
Or, you can download a free trial version right from the Microsoft website and see if you think you'd benefit from having One Note.
One thing you could get used is the fridge. Every year, thousands of students buy a fridge for the dorm and then want to sell it the next year, when they have an apartment. You might also want to see if your roommate will have one or will want to share one and pay for half of it.