A recent article noted "an estimated $1 trillion to develop, purchase and support [the F-35] through 2050." The F-35 has, indeed, acquired the notoriety of being a "trillion dollar program." That characterization is inaccurate; it is more than that.
The 2010 DOD Selected Acquisition Report (SAR), attached, noted the F-35 "operating and support cost" (O&S) at $1,000.5 billion (then year dollars). (See the last page.) There's the trillion dollars, but you also need to buy it first. According to the new GAO testimony, the acquisition cost is $397.1 billion (then year dollars). (Find the GAO testimony at http://www.gao.gov/assets/590/589454.pdf; see the table on page 4.)
Make it $1.4 trillion.
Both the O&S and acquisition costs will be going up.
As GAO noted, the $397 billion was an "interim" estimate, and it will be increased in the next SAR in April.
The O&S cost should increase as well. I had an interesting conversation with an Air Force cost expert. He quite literally smirked at the SAR estimate that F-35 costs would be just 20-30 percent more than F-16 flying costs. The F-35 is far, far more complex; that number is going no where but up. He expected significant increases in that estimate.
Anticipating those increased cost estimates assumes an honest system estimating costs for the F-35 in DOD. We do not have that. Management is trying to suppress the cost increases. Having the final word, they will surely do so. They know how to do this; it has happened in the past.
Whatever increased costs you see in upcoming DOD documents on the F-35, expect more in the future.
There is, of course, the option to reduce the buy, as they inevitably will. That will decrease the bottom line, of course, but also increase the unit cost.