I have hoarded Optus $30 sims for $10 and usually port into Vodafone $2 sim before porting out to Optus again.
However, it appears that Vodafone has finally caught on because they are forcing a recharge before activating the sim.
What providers, besides Optus, don't force a recharge on activating their $2 sims?
Telstra free $2 sims online don't require recharge.
But would it be possible to just port from optus to optus?