Any new computer purchased with WIndows Vista with qualify for a free upgrade to Windows 7 between June 26 and January 31, 2010
Check if you school or academy is with the Microsoft Developers Network Academic Alliance(MSDNAA). If they are, check the MSDNAA site when the final version of Windows 7 comes out and distribute it.
Check with Microsoft DreamSpark
Check with Journey Ed whether you got a discount or not.