You can get a Mac and run your Windows programs. The only caveat is that you have to install Windows on your Mac. Not a problem, and not hard to do, but if your school does not supply Windows OS for free, you would have to buy the student edition. That may cost you as much as Office in a few cases. However, you would still have a Mac for less than $1000.
The home and student edition of Office 2011 is as low as $100 without Outlook. You can buy the Windows 7 upgrade for $30, but you have to have at least Vista to install on the Mac first. Using Bootcamp, it cost nothing to have both Windows and OSX on your Mac. And it gives you a great set of options for the future. if you decide to buy the Apple versions of office in the future, you have that option.
Your purchase options are these for buying a Mac.
$700 Mac Mini, you provide the monitor, mouse, and keyboard. Usually not a problem for most PC users.
$1000 MBA 11", MacBook.
$1200 MacBook Pro, iMac.
$2500 Mac Pro.
You save at lest $50 for student discount, but better prices can be had from the Apple Store refurbished units. Prices over $150 off new are common, and they have the same warranty. I usually buy refurbished with never a regret. You hav to wait sometimes for a particular model. Tonight, I saw a iMac 21" for $929.