The latest email I got today details some new things.
This may be targeted, but have been given this promotion:
.
It is. I noticed wording at the bottom saying this is only for member number xx_.
So how much is the cheapest recharge voucher, I don't need a second SIM, but is it cost effective to just throw away, or briefly use up the credit?
From the link there's a big banner saying $20, 30 and $50, and that's pretty consistent with others. As for cost effectiveness, I'd say not but maybe if you only need 500 points for something specifically, it's an easy way to achieve it. I also note the conditions said 500 maximum, so there's no point to buying multiples for more.