Some will be cheaper if purchasing multiple items as you can use better discount codes as your minimum spend increases. You can see by looking at the %'s I've put next to the coupon codes.
Bit sad that there are so many strange exclusions from Myer's 20% off lego.
Not usually the historical lowest, but pretty close!
$422.39 (PSAVEIT 7%) (Usu $599.99) Technic Bugatti Chiron 42083 https://www.ebay.com.au/itm/233043972943
$281.56 (PSAVEIT 7%) (Usu $399.95) Technic Bucket Excavator https://www.ebay.com.au/itm/232807202938 RETIRING - BUY IT NOW!
$179.96 (P10LESS 10%) (Usu $249.95) Technic Mack Anthem 42078 https://www.ebay.com.au/itm/232764212595
$143.99 (P10LESS 10%) (Usu $199.99) Lego City Passenger Train 60197 https://www.ebay.com.au/itm/233043971552
$119.03 (PSAVEIT 7%) (Usu $159.99) Lego City Downtown Fire Brigade https://www.ebay.com.au/itm/233042477236
$119.00 (PSAVEIT 7%) (Usu $159.95) Lego City Mining Experts Site 60188 https://www.ebay.com.au/itm/232732792468
$91.19 (PURCHASE5 5%) (Usu $119.99) Lego City Sky Police Air Base https://www.ebay.com.au/itm/233042477171
$62.07 (PICK3) (Usu $79.99) Star Wars Droid Gunship https://www.ebay.com.au/itm/233041064617
$106.36 (PURCHASE5 5%) (Usu $139.95) Ninjago Quake Mech 70632 https://www.ebay.com.au/itm/232770027097
As per https://www.ozbargain.com.au/node/439933 also:
Lego 75192 Star Wars Millennium Falcon $964.96
Lego Star Wars Death Star 75159 $564.96
Original PURCHASE5 5% off Sitewide on eBay Deal Post
Original Sitewide Spend & Save on eBay Deal Post
Good find but Myers prices of the regular sets even including the discount still puts it on par or even higher than other places. The draw cards would be the exclusives like Death Star, MF and the larger Technic sets