Myer online has the Cygnett Chargeup Pro 20,000 mAh for $84.97 was $169.95. The rest of the Cygnett line is up to 50% off.
Chadstone has 3 in stock.
They also have 40% off selected Belkin stock.
One thing good about the chargeup pro 20k versus the larger 27k is it can also charge at 12v/3A which is required by some HP laptops as HP implements some sort of charging lock which prevents non-HP chargers to work.