3) Prince Sultan bin Mohammed bin Saud Al Kabeer – Net Worth: $4.2 Billion

This 60-year-old self-made billionaire is a member of the Saudi royal family. He is the founder of the Almarai, one of the largest dairy operations in the Middle East. He founded the company in 1977 and took it public in 2005, retaining 28.6 percent stake in the same.