For anyone that picked up a $29 SodaStream here: https://www.ozbargain.com.au/node/646372
Now you need some additional bottles, best price by far appears to be Target: SodaStream Fuse Twin Pack 1L Pepsi Max Edition Carbonating Bottle for $5
Click and collect for $3, or no charge with $20 order. Don't forget Cash Rewards.
$20 minimum for free c&c :(