Called up Optus as I was thinking of moving to TPG but they offered me their new set of plans, apparantly released today!
$49.99 = 50gb + 70gb offpeak
$59.99 = 75gb + 75gb offpeak
Both prices include a $10 discount for bundling with home phone, but if you are currently getting any free months you'll lose them (thanks Nowheredotcom)
Peak = 12pm-12am
Offpeak = 12am-12pm
Both Downloads/Uploads are counted.
No details on their website yet.
If you're on one of their older plans (i was on 20/40) you'll also get doubled internet speed as these plans have 20mbps download and 512kbps upload. No lock-in contracts if you're not already on one. They also offered me $10/mo off my home phone. I was told the upgrade would apply from 1st May.
I have cable internet so I can't guarantee this offer goes with ADSL as well - maybe someone can confirm.
I note that there's a 24 month lock-in and that the off-peak allowance halves after the first 12 months.