The C130 MPA probably would a better solution with the longer range and cheaper than the P8
The NZ government is great like the UK having "wish lists" that don't materialise
NZ - F16, 8 x C130J, 3 x ANZACs etc
UK - 150 x F35s, 21x Nimrods, 25 x A400, 12 x Type 45s etc
So don't assume P8s are going to happen
Umm... No.
IIRC the cost for the P-8A Poseidon is expected to be ~USD$200 mil. per aircraft. That is for the aircraft, avionics fitout and integration, etc.
The base cost of a B737 (which the P-8A is based off) is between USD$51 - 87 mil. depending on model and fitout. In other words, the extra USD$110 - 150 mil. in cost is for avionics development and integration, airframe modification to accomodate sensors, hardpoints and a bomb bay.
The base price of a C-130J is ~USD$66 mil. I am certain that LockMart could put together a comprehensive MPA package which could fit aboard Herc II. After all, LockMart did put the palletized MPA package for the USCG HC-144 Ocean Sentry (CN-235MPA) in. What seems to have been overlooked though, is whether or not LockMart could put together an MPA/ISR package as comprehensive as that intended for the P-8A, with a significantly lower cost. Personally I do think that LockMart could put out an MPA version of the C-130J which is very capable, possibly even a rival for the P-8A. However, the cost would almost certainly also rival that of the P-8.
One thing I do disagree with other on (albeit with some caveats) is whether or not it would be a good idea for the RNZAF to invest in some smaller, twin-prop manned MPA aircraft. IMO it would be a good idea, particularly if an order was placed soon and IOC reached this decade.
My thinking is this. Right now Kiwi P-3K Orions conduct maritime surveillance flights of the NZ EEZ, as well as the EEZ of a number of S. Pacific island nations. In some cases, there are some rather long transits for the P-3K's to get on station, and there are only six P-3K's in inventory.
With the way things are looking, the RNZAF is likely to only get four P-8's, which means that while the individual aircraft is more capable, there is still a definite limit to what can be patrolled due to the limited number of airframes. Having a number of additional smaller, manned MPA could allow more patrolling of not only the NZ EEZ, but also the EEZ of those island nations. What I would look for would be a capable design which could potentially be useful in a hostile environment, but also have low operating costs and basic operating requirements. In essence, an MPA which could be flown to one of the island nations and operate from an airport or airfield there, then return to NZ.
I would prefer not having a UAV simply because a UAV just provides eyes in the sky, and could not reasonably be fitted with dropable stores (be then ordnance or storpedoes). Also operating a UAV from a foreign airfield could run into ATC and maintenance issues.
-Cheers