From 2013-2016, the University of Georgia estimates that it has saved students $2 million .
Here's an excerpt from the announcement:
The University of Georgia is actively engaging in the promotion and adoption of OERs by providing faculty members, especially those who teach large enrollment courses, such as those included on the University System of Georgia Top-100 Undergraduate Enrollment list, with resources and assistance to transition away from expensive textbooks to open education resources. Since the OER initiative began in 2013, OERs will have saved UGA student $2 million in textbook costs by the end of 2015-2016.