UCB’s Software Central offers EndNote licenses to students and departments. The license does not expire once purchased, but they will stop offering these licenses as of February 28, 2010. The license costs $65.99 and is available for both Windows and Mac. Complete information is available from Software Central.
After February 28, you can still purchase EndNote at a substantial discount ($114.98) here. The non-student “off-the-shelf” price of EndNote is currently $299.