Many internet users in the ACT would be signed up with TransACT/Grapevine, which was acquired by iiNet a little while ago.
iiNet now offers a plan for $90 / mth of 1000GB download. If you have signed up with TransACT/Grapevine you can switch for free and it's probably cheaper than what you are on.
TransACT terms are here: http://www.iinet.net.au/internet/broadband/vdsl2/transact/
Plans are here: http://www.iinet.net.au/internet/broadband/vdsl2/transact/. Cheapest is $60/mth for 100GB at lower speed.
Thought I'd share because this is going to save my household $120 / year while eliminating concerns over data usage.