Build and sell is the least worse option; bit like a builder finishing a house and selling at a loss rather than write off the initial outlay.
As I said before, sell it to the French. Amazing that though - bring Nimrod and HMS QE together and that's something like £6.0 billion down the drain. Apparantely, it has been announced that there will just be 12 F-35Cs deployed on HMS PoW in 2020 and not 36. They haven't given a number as to how many F-35s will now be ordered. Might as well built a LHD in the first place.