Moonbase by 2022 For $10 Billion, Says NASA

"Based on the experience of recent NASA program innovations, such as the COTS program, a human return to the Moon may not be as expensive as previously thought. The United States could lead a return of humans to the surface of the Moon within a period of 5–7 years from authority to proceed at an estimated total cost of about $10 billion (–30%) for two independent and competing commercial service providers, or about $5 billion for each provider, using partnership methods."