It was a long time coming, but Australia has finally made its decision. As part of a multiyear, multibillion-dollar effort to beef up its defenses to face down an expansionist China, America's ally Down Under has tapped Britain's BAE Systems (NASDAQOTH: BAESY) to build nine shiny new Hunter-class frigates -- for $26 billion.Here's why I think that makes BAE a bargain at current prices.BAE stock has underperformed the market this past year -- but don't wave the white flag just yet.