MSOCS,
From a UK Govt perspective, we are buying X many aircraft at "various" prices as we slide on down the production cost curve over time. 500 British companies manufacture components for every F-35 built (or to be built), most of which are agnostic of variant. So, over the life of the Program, those 500 British companies earn revenue from Y (total Program build) aircraft and pay tax to the Exchequer on those earnings. Y is much greater than X and the concomitant tax on Y is around 2-3 times the predicted cost for X.
We are now back to my original quote to you, you can't assure nothing... I asked you two specific questions and received back fog rolling in from the bay...