Billionaires are creating multi-million greenback properties on mega-ranches. Sales agent Robb Nelson says it be a exact property “Bonanza.” Veteran Novel York City Mayor Michael Bloomberg paid $46 million for a 4,600-acre ranch in Colorado. A 41,000-acre ranch in South Dakota is going for $37 million. It entails five bedrooms, a fully equipped fitness center and a house theater. The ranch is also a cash maker with crops, over 2,000 cattle and hundreds of wild mustangs.