Check this out: http://nwn.blogs.com/nwn/2013/03/second-life-education-non-profit-discount.html
Hamlet's New World Notes reports today that Linden Labs has quietly been offering sim discounts to some selected non profits and educational groups who have previously given up their sims. Apparently LL used to do this regularly but discontinued the practise . According to his blog feedback there is a ton of controversy around this subject. It is well worth reading. I won't repeat it here, but just send you on over to New World Notes for the scoop.