On Monday, the U.S. Defense Security Cooperation Agency announced that it has notified Congress of a possible Foreign Military Sale to the government of South Korea. If approved by Congress, prime contractor Northrop Grumman (NYSE:NOC) will sell four of its RQ-4 Block 30 (I) Global Hawk spy drones, along with "associated equipment, parts, training, and logistical support."

The Global Hawk, one of the largest and most complex unmanned aerial vehicles (UAVs) in the U.S. arsenal, carries a correspondingly large price tag. The bill for this sale comes to an estimated $1.2 billion, or $300 million per UAV.

DSCA notes that the Global Hawks are being ordered in connection with a handoff from U.S. military forces to those of South Korea of "primary responsibility for intelligence gathering" on the Korean peninsula, slated to take place in 2015.