Optus Broadband - $30 rebate.
They did/do have a $0 connection fee up but read on for more about this.
If your a preexisting customer bundle it together with your mobile or landline and they'll drop $10 per month off the charges.
If you can get all of these bits you end up with $169 for a years 256k connection (havent included the connection fee in this so add that in when you know what it is).
Now - here's where things get blurry again. When you go into the sign up process Optus are still touting the free connection when you bundle with other Optus services - so it may be available.
Add to that - there is a promotional code around at the moment BBkW2 which gives you 2 months free, but codes may not always work so be cautious on relying on it. So - although Optus arent the cheapest you can find if your looking at starting up with them on a light service this would be a cheap way to get in there.