In July, President Trump announced the two countries had reached a "full and complete trade deal." According to the White House and a South Korean press release, the trade deal would
Lower South Korea's country-specific IEEPA tariff to 15% (effective August 7); Lower Section 232 auto tariffs to 15% (not yet implemented); Provide South Korea with most-favored nation (MFN) status for potential Section 232 tariffs on semiconductors and pharmaceuticals (see below); Commit South Korea to purchase $100 billion worth of U.S. energy; Commit South Korea to invest $150 billion toward U.S. shipbuilding and $200 billion in certain sectors, including semiconductors, nuclear energy, batteries, biotechnology, and critical minerals; and Commit South Korea to ease some nontariff barriers to U.S. imports.
Not Delfin specifically, but there was theory floating around that Delfin 1 & 2 would be built in Korea and 3 might be built in the states as part of this agreement.
To pull a move from the XL playbook: 150 + 200 = 350.