New developments:

http://www.defense-aerospace.com/articles-view/release/3/139774/new-dutch-government-changes-fighter-plans.html

In the words of @MadRat: Phase out F-16’s and add just a small contingent of leased Gripen. By shifting hours around on F-16 airframes you can keep numbers up on the best candidates to last through to the transition. Gripen is mostly ready for NATO compatibility so leasing is a great option.

That way they also have a first hand info on Gripen system
when it’s time to decide, but above all bought time for accurate info on what
F-35 will cost the state.

Sounds like a very practical solution to me! Committing to F-35 without knowing the purchase price within a window that gives known extra F-16 costs, without knowing operating cost and without knowing that it will be available in the window needed is… RISKY.

Minister Hillen has gone on record saying there is budget for at least 56 JSFs.

According to defence-aerospace the report says:

“The investment budget reserved by the Ministry of Defence is not adequate to replace the current number of F-16 aircraft (68), never mind to procure the planned number of JSFs (85).”

“In June, the Ministry of Defence estimated the cost of 85 JSFs at €8 billion. It had reserved no more than €4.5 billion to replace the F-16s. Of this sum, €4.05 billion is still available.”

Either the Dutch Court of Audit has got it wrong or the minister has got it wrong. €4.05 billion might buy 56 F-35’s but will not suffice to bring 56 F-35’s into service so I am inclined to believe the Dutch Court of Audit whose job it is to ensure that it gets its figures right.

The court also said:

“The Ministry of Defence will have to apply half its total capital expenditure budget for seven years to order 68 JSF aircraft and for nine years to order 85 aircraft. Given this budgetary impact, it seems inevitable that fundamental decisions will have to be taken on other weapons systems, which might also affect the navy and the army.”

56, 68 or 85 F-35’s would mean a minimum of 6 years of F-35 taking 50% of the Dutch military spend on equipment. The way I read it that would involve major spending reductions on other procurements and a corresponding reduction in overall capability.

Court of Audit’s afterword
The minister chiefly confirmed our conclusion that the Ministry of Defence needs to take fundamental decisions on the composition and capability of the Royal Netherlands Air Force. If 56 JSFs were procured, the operational objectives of the armed forces, and thus the Netherlands’ contribution to NATO, would have to be reconsidered.