First, let's clear the misconception of cost effectiveness. An F-35 shooting down a dingy Su-24 amortized way back in 1992 would be entirely worth it, if Su-24 was on a mission to strike your C&C centre or naval port. No different really than using a $50,000 guided bomb to destroy Taliban encampment with $800 worth of rusty AKs and a pick up truck. If it solves the military objective and you can afford it, it is a good solution.
Long term, strategically, cost is important, sure. Prolonged world war, major players scale. Short term, no. And in a conflict, minor players have short term only operational horizon at their disposal.
> What's most interesting to any buyer is for X billion dollars, and N years of flying, what capability can I get?
Norway found the cost manageable, in competition with other bidders. And for comparison, a municipal garage of the parliament in Oslo now stands at the cost of three F-35 acquisitions.