That policy rule needs changing. Who can get it changed and when? It makes no sense whatsoever and Im not aware of any other domain extension in the world having a 6 month no sale allowed rule.
Sometimes I think Auda is trying its hardest to stop Australia's online success.It certainly has slowed it down where we are years behind the rest of the major extensions rules wise
some ideas
1. maybe email back you are not in a position to offer the name for sale at this time and send them the part of policy thats says 6 months rule.
edit...
This happened to me last year. I said that I hadn't considered selling the name and that it was prohibited within the first 6 months anyway.
I invited them to make me an offer after the 6 months was up... they then came back to me at that point and I sold it to them.
Seems like a pretty good parallel situation. Was it another domainer or end-user? And how much did they offer?
Tell them the truth
You want to sell it