If you mean by RA as a US school, one of the least expensive is Amberton University in Texas. http://www.amberu.edu/ Check Jonnies site http://www.geocities.com/SiliconValley/Haven/2386/distance.html I would also suggest Dr Bears'guide to the best MBA's and their 14th ed Bears Guide ti distance learning Dan
I do believe Amberton wins the prize as "low-cost provider". However, if you can pinch a few more pennies there are a few programs which are both reasonably priced (around 10K) and of world-class quality. Heriot-Watt (Edinburgh Business School) Royal Holloway University of Leceister
Actually, I probably have to correct myself. With current exchange rates there are probably South African or Australian programs which are lower.