GAO report about the evolution of the Joint Strike Fighter (F35-JSF) program
Table about JSF Program Cost and Quantity Estimates over time
Full rate production is now planned for 2019, a delay of 6y from the 2007 baseline. Unit cost estimates have now doubled since the start of development. Initial operational capability dates for the USAF, the USN and the US Marines have slipped over time and are now unsettled.
ref: GAO-12-437, June 2012, page 05