The aircraft carrier Gerald R. Ford (CVN 78) is the most expensive ship ever built by the US government, and quite possibly by any government. No one knows the true price given the various computational ways to figure the costs of design and development of the ship and its various systems, building the carrier and buying thousands of installed systems and components, and getting all those systems to work as intended. The final bill isn’t in, but all things considered, it is safe to say it will be somewhere north of $15 billion.