You can preorder the S10 128gb at Woolworths. Free Samsung Galaxy Buds worth $250. The cheapest plan is $65.78 which gives you unlimited calls/sms and 3gb. However when signing up you get 15 gb bonus data. You then get another 20gb every 3 months (they call it school holidays bonus), but you need to add it manually. The data rolls over and is kept in a bank up to 100gb. Hence you would have approximately 10gb a month with the bonuses. If you finish all the data internet stops, but you can decide to add on 1gb @$10.
Also you can add unlimited International calls to 10 countries + 300min to 21 countries for $5. It used to be $15 few weeks ago now reduced to 5.
Check here about the bonus data https://mobile.woolworths.com.au/offers/bonus-holiday-data.h...
Don’t forget $50 cash back via Cashrewards.
Overall cost $1578.72 ($1528.72 if you count cashback)
If you are willing to pay $75,78 you will get 10gb data plus the other bonuses (which will take to approximately 17gb a month).
Woolworths uses Telstra.
Other models for 3gb plan
S10 plus $72.03 a month