Google has just announced unlimited storage with Drive for Education
Unlimited storage: Store as many Google Drive files, Gmail messages, and Google+ photos as you need. Individual file sizes up to 5TB will be supported.
This is Free for Education!
"..Drive has become the cloud storage and sharing solution for more than 190 million people worldwide who use it regularly at home, work and school. For many of the 30 million students and educators using Google Apps for Education.."
here is the official blog post