Was trying to make a booking for 2 hours today and came across this one. So booking for 3 hours!!
“For a limited time, book online now and save up to $8 online or $17 drive-up.
Park for up to 3 hours at P7 International car park for a flat rate of $19.90.
For the valid parking period 15 October 2019 to 15 December 2019.
Maximum of 200 car spots available per calendar day, so be quick and take advantage of this limited promotion. Book now.
Pre-booked Quick Trip tariff is non refundable inside 24 hours prior to your booked date and time of arrival at the airport. Do not park in Guaranteed Space on Level 2 as penalties may apply.”
About $19.90 too expensive, but that's Sydney airport for you.
Not only will they charge you sky high price for parking, they also force you to walk through the duty free shop for departure.