So this one requires a bit of effort.
I found the cheap dates on flightscout more easily, but you can just do a search on byojet.com.au for the dates you're after if that suits.
Then at checkout, use the code FOLLOWTOFLY30 (https://www.ozbargain.com.au/node/404237) for $30 off.
Result is the prices in the title.
Example of upcoming one is 09 Nov 2018 - 23 Nov 2018 for OOL to SFO.
Airline: Air New Zealand
From : SYD, MEL, BNE, OOL
To: SFO/LAX
Inspired by similar but different dates/prices seen on iknowthepilot post (https://iknowthepilot.com.au/flights-to-san-francisco-usa-fr…) (to SFO only), so do check both (don't know why it makes a difference, or if I'm just seeing things)
Layover in Auckland airport. I have done this - it is not fun. Qantas is only about $80 more and it's non-stop.