Auckland to Hong Kong $567, Tokyo $564 Return on Fiji Airways
Here is a very cheap flight to Hong Kong on a full service airline with a long layover in Nadi, Fiji on the way (can't make it into stopover). I had no idea Fiji Airlines even flew to HK. Dates are showing August to November despite what Fiji Airways site says. Fares include seats, meals and bags. Almost the cheapest airfare to HK.
Find the cheap dates on Google Flights then plug them into Skyscanner , Momondo etc.
Supposedly other NZ cities are on sale as well but I can't find the cheap fares. Will update when I find something.