NCSX was estimated to cost $70 M when the FY 2003 budget was submitted to Congress in 2002. It was later "baselined" at $102 M when approved in 2005. In August 2007, Princeton told DOE the cost would rise to $142 M. In February 2008, Fonck told the DOE's Fusion Energy Sciences Advisory Committee (FESAC) the project would cost $152 M and was being reviewed, with a decision on its future to be made in June after a series of technical, cost and schedule reviews. In mid-April, Princeton told a DOE review committee (so-called "Lehman Review") that the cost had risen further, to $170.2 M. The committee was told that $76.4 M had been spent through January 31, 2008 and that the project could not be completed until 2013.

Although a FESAC panel gave the project high marks for technical importance, finding the additional funds to complete the project has become problematic. DOE and OMB budget guidance for fusion has dictated program planning based on cost-of-living only budget growth for non-ITER fusion programs during ITER construction. Furthermore, DOE has recently told Congress, as part of the FY 2009 budget submission, that the estimated cost of U.S. contributions to ITER construction have risen from the previous "cap" of $1.122 B to an estimated range of between $1.45 B and $2.2 B. DOE expects to narrow this range after the ITER Organization issues a new baseline ITER design and construction schedule this Summer.

Although a decision on NCSX is expected in June, sources indicate the decision date could slip by several months if DOE decides to conduct further reviews and to seek funding relief during the FY 2010 budget preparation cycle.