If we're honest then the MRA4 should have been cancelled years ago and well before we spent $4Bn on it. Yes the MOD probably tooled around with the specifications but flying in a straight line is probably not one of the things that they got wrong.
The decision to purchase MRA4 was primarily political - by the last Conservative government. The decision to continue with the farce was Noo Labour. Overall then, this had little to do with military capability and everything to do with greasing the palms of contractors and the workforce.
The point I think is that the UK could probably get away with this nonsense when the government was prepared to spend a reasonable amount on Defence. The current bunch are not (perhaps they could bail out BAES from the International Development slush fund), still want to use the armed forces and labour under the utter illusion that British Industry automatically builds the best equipment in the world. In some cases they do but we need to buy what we need on the basis of its merits.