NaB - We an easily get wrapped around the axle when we start talking about design and build costs for carriers. That is (relatively) the inexpensive bit. Even in the US it is possible to show that building Fords is "affordable" in terms of new-ship money per year, because of the carriers' long life.
But F-35Bs are not cheap to acquire or operate, and nor is Crowsnest - and so far it appears that 48 F-35s are all that can be afforded for a long time to come.