1GB of internet / month would be enough for me. Don't mind buying a new sim every month. So far I found these options:
Lyca $6 for the first month with TopCashback - but I had very bad experience with them, and I'm not alone
Felix $12.50 with TopCashback (-$5)
Lebara $9 for the first month (yeah, looks like previous $7 deals are no more)
Anything cheaper?
Not cheaper but an alternative
Amaysim $10 sim @ Woolworths till cob Tue.
( $30 sim discounted to $10)
28 day validity.