I posted something similar to this on OzBargain. The deal is you get free accommodation for stopovers bigger than 6 hours. So potentially you can score 2 nights free hotels which allows you to check out the city for the day. Hainan's Transfer Accommodation Service
Fares include 2 checked bags & food as well. Hainan is a 5 star airline.
- Auckland-Chengdu $643 - Skyscanner - $677 if booked directly with on the airline's site.
So for example:
Leaves Auckland at 10:30AM and gets in Shenzhen at 6:35PM. Off to the check out Shenzhen and a free hotel for the night. Flight to Chengdu leaves at 7:55AM the next day.
What's in Shenzhen? Some very cool markets especially for electronics. Check out how this guy built an iPhone from scratch and the Reddit thread. Chengdu is nice as well. Have been there. See the Panda sanctuary.
Tianjin Airlines are offering cheap direct flights to various destinations. These flights include bags & food. No freebie hotel as it's a direct flight.
- Auckland-Chongqing $502 - Skyscanner This is a direct flight. Hainan is also offering this flight for $50 however this is a codeshare with Tianjin.