If you don't need Fully synthetic for an older car this is okay oil. Not as cheap as previous but I haven't seen any big brand oil as cheap as this recently.
Check if it suits your car by checking your car manual or with Rego2Oil https://rego2oil.castrol.com/en_au/australia/
Supercheap Auto will price match and beat it (by 50c) if you contact them on online chat.
specs from previous deal:
Castrol Magnatec 10W-40 is suitable for use in automotive petrol and diesel engines where the manufacturer recommends an ACEA A3/B4, A3/B3, API SN/CF or earlier specification 10W-40 lubricant.