There is no doubt that the reunification of the Korean Peninsula will be an extravagantly expensive affair, but this will soften the blow for those in the South (this is something the West Germans did not have to look forward to):

North Korea is one of the world’s most impoverished states but its value of minerals is estimated at $2.14tn, or 30 times that of the South’s resources, according to the Industrial Mineral Bank in South Korea… South Korea’s state-run Korea Resources Corp. plans to begin importing minerals from North Korea by this February, marking a significant step towards joint exploitation.

China, searching the world for natural resources to feed a fast growing economy, is also eyeing North Korean mineral ventures and recently signed an agreement with the country to jointly explore and develop oil fields. They gave no details about location but Chinese geologists estimated in 2002 that offshore fields in the Yellow Sea off North Korea may contain 21.9bn barrels of oil and gas.

Of course this one of the reasons that North Korean territory is attractive to China (e.g., Goguryo claims). The next few decades will be interesting.