Wgton to Auckland is currently $29 night flight from Air NZ. But they won't let you parachute out half way there.
Otherwise, standby from Auckland to Napier is about $55, and then a bus from Napier to Hastings is about $4. You need to walk from the Napier airport to the nearest bus stop in Napier which I think is the 15 bus route ( Ahuriri )