Well, the numbers that the Israelis are seeing :

“Defense News” reports that Ministry of Defense and Israel Air Force officials are “stunned by projected program costs for their Israel-unique version of the F-35” Joint Strike Fighter (JSF), manufactured by Lockheed Martin Corporation (NYSE: LMT). IAF and Ministry of Defense officials are struggling to pare a hefty list of customized subsystems and add-ons that threaten to ground the aircraft as unaffordable.

“Defense News” states that, in September, US F-35 program officials gave rough price and availability data to their Israeli counterparts, who reacted with sticker shock to the price tag of $200 million per plane. Since then, both sides have been seeking a new configuration that can meet IAF performance and budget requirements. The IDF had expected to pay about $2 billion – $80 million per plane – for the first 25 aircraft.

My money is on the Israeli numbers being closer to the truth than the Norwegian ones.

Doubtless, there costs with integrating Israeli systems into the airframe, but it’s increasingly clear that the high end estimates for cost are accurate, and largely unaffordable.