Open Learning Initiative, a project of Carnegie Mellon University, offers course packages at low-cost; many have a price-point of $25/student. Payment can be made by the student and can be set-up through the Bookstore to allow use of financial aid funds; alternaively, the institution may pay the cost directly.
The State of Florida's Affordability Counts initiative awards medallions to courses for which costs do not exceed $20 per credit hour. All course information can be found at this website. Data on the program is also available.