I went travelling with a colleague and he didn't have a Qantas Frequent flyer account and we found 2 links that let you sign up up for free!
https://www.qantaspoints.com/join-now?code=INGOGO
https://www.qantaspoints.com/join-now?code=luxuryescapes
Usually this is $99.50. I don't think there's an expiry (possibly until ozbargained) so get in before it's no longer available!
Enjoy.
I think if you have ever paid for a QFF account, you should just hand in your Ozbargain license and be banned from this website.