Deep Space Industries issued a press release yesterday estimating the value of the small asteroid whizzing past Earth this week at $195 billion.
That figure is based on the type of asteroid it is and assumes certain quantities of water ice, iron, precious metals, etc. DSI plans to send tiny probes to such asteroids to determine exactly what resources each asteroid contains. Once that is established, a value can be placed on the body, and mining operations can be considered. That's when the real fun will begin.