Not the best price but a decent price. Part of Autobarns 'Penrite Month(autobarn.com.au) sale'. There seems to be varying discounts across the entire range.
HPR 30 20W-60 Mineral Engine Oil 5L - $39.99(autobarn.com.au)
10W-40 Semi Synthetic HPR Diesel 10 Engine Oil 10L - $79.99(autobarn.com.au)
Radiator Flush 375ml - $9.99(autobarn.com.au)
Still too expensive