Spotted this at my local Kmart (Stud Park) and thought they were amazing prices for what you get.
Oppo AX5s is the 3GB RAM / 64GB Storage version and locked to Optus. The red variety was definitely $45, but can't 100% confirm that the Black is the same price.
Other places are still selling it for ~$189-$229
Specs - https://www.gsmarena.com/oppo_a5s_(ax5s)-9626.php
Samsung Galaxy A30 is 3GB RAM / 32GB Storage and also locked to Optus.
Other places are selling it for ~$300
Specs - https://www.gsmarena.com/samsung_galaxy_a30-9579.php
That being said, if I had to pick between the two, I would recommend paying the extra $15 for the A30 is a much better phone, where even though it has less storage, it has a higher resolution screen and is AMOLED, so it looks just as stunning as the flagship phones (just with lower performance). The A30 also runs Android 10, compared to the AX5s' Android 8.1 with Color OS (security updates from December 2020).
EDIT: Here are the receipts for the two phones - https://files.ozbargain.com.au/upload/54993/87237/20210226_1…
Are any of these operator locked phone, unlockable? I know that you can get some codes on ebay to unlock, but the last time i tried it was years ago, so not sure if that's still even possible.