The Parent Visa 103 is a non starter as the waiting list is so long you'll have to wait 30 yrs (yes 30 ) to get it. See:
https://immi.homeaffairs.gov.au/visas/getting-a-visa/visa-processing-times/family-visa-processing-priorities/parent-visas-queue-release-dates
So apply 30 yrs before you retire. The contributory Parent Visa is soooo expensive.