The cost of the cat n trap conversion quoted has always been suspect, because it (allegedly) includes a whole raft of things (eg AAR capability) that are add-ons to the wider capability. There is an element of comparing apples with clothes pegs here. Whether all LOD should be included in costing can be argued either way. However - two things are clear :
1. We are paying more than we should have done for the two ships. This is largely due to the incredibly incompetent way that MG and production contract decisions were used as a political football by the last lot and by inter-service rivalries. Nevertheless, the money is "spent", we are buying them and they are coming along nicely.
2. Because they are big ships with (very) large margins, they will not suffer the sort of limitations that CVS did. Over a fifty year life capabilities can be added - particularly when capability is largely vested in aircraft. Some may be surprised to learn that initial buys of aircraft can be added to over the years, although I'll admit that that's now the exception rather than rule. Still, C17 numbers have doubled from the original "interim strategic airlifter" plan, Wokka numbers have also increased - it can be done.
Arguing about what this will eventually look like now is a bit like trying to decide whether your six-month old nipper is going to be a Nobel prize winner or a regular contributor to the Jeremy Kyle show.