Ah ah, the old chestnut it must be Hokitika to Christchurch.

Look at 7 April to Samoa, from Christchurch $208, from Hokitika $900 - last flight out of Hokitika to Christchurch is $264, so charging $692 to go Hokitika to Christchurch, Hokitika to Auckland on last flight of day is $592, which means that 900 - 592 = $308 for a fare from Auckland they say is only $158 (Auckland to Apia). Yes heard it all before pay a bit more for misconnects etc - not what the advertising indicates.
A lot of the time it is cheaper for us to fly to Aus via Auckland than it is to fly via Christchurch even though we have to fly to Christchruch to get to Auckland

Quick look elsewhere and ranges from $617 to $258 for Hokitika to Apia, actually get a choice of flights out of Hokitika unlike NZ site which does not give that choice!!