"The estimated cost is $1.071 billion.”
Wrong, the estimated cost is the figure quoted + the wasted £3.6 Bn by cancelling MRA4 + the cancellation and disposal costs + the additional, as yet unquantified, cost of another manned platform (+ training costs + support costs).
Why do you think the USA have gone for a twin pronged approach? The study the DOD commissioned on replacement of the P3 concluded that, whilst RPAS platforms could bring something to the party, you still needed a manned platform (just not so many).
So either Uncle Sam has got it wrong, or we know better.
Wanna take any bets?