Please follow below steps for $699.8
1) Price match with camera warehouse at sony store https://store.sony.com.au/lenses-zeiss/SEL55F18Z.html for $869.42.
It will be added to your cart in a few minutes after approved. ( prior to that you can also create your ACCOUNT at sony)
2) Visit sony from Cashrewards https://www.cashrewards.com.au/sony site to sony for an additional 8% cashback.
3) Purchase at $869.42
4)You will be automatically eligible for cashback from sony ($100). No need to fill claim form as you bought from sony online.
Final price will be $699.8