Singapore or Beijing Return from Christchurch $639, Auckland $645, Wellington $642 Return via Qantas & Emirates
Qantas is offering cheap fares to Singapore and Beijing. Flights include bags, meals and seats. Dates are January through August. All flights stop in Sydney or Brisbane. You can schedule a stopover in Australia for a day visit.
Beijing Qantas prices are about the usual sale prices but lots more dates. Singapore prices are the lowest I've seen on a full service airline.
Qantas seems to be doing a 12 days of Christmas sale (see their homepage) so Singapore might finish tonight whereas Beijing should last for a while.
As usual, find the cheap dates through Google Flights then plug them into Skyscanner.