Given the specialised role for most of these vehicles it's hard to see what would be served by going to the cost of repatriating them (other than not losing the good will of voters or Daily Mail readers) - probably not much use for them shuffling troops between Colchester and Salisbury plain I would think. Spending all the money on such a highly specialised vehicle was the first mistake, paying to ship them back and then languish on a UK airfield will be the next.