This is a tough one to put a value on....
Obviously it wouldn't appear that their is an Australian trademark issue (presently), but if DMOZ ever wanted to launch geo local directories, they could probably get it off you given that it was registered to take advantage of their international brand, but them expanding internationally is unlikely anyway.
So that's a minor drawback.
I think the bigger draw back is that when you search for dmoz in google.com.au you get international results rather than Australian results, so if you developed it you'd be unlikely to rank for what would be a very competitive term. You are also unlikely to get type in traffic for it given that dmoz is a dot ORG domain and no one would think to type in dmoz.com.au for.
Then of course there is the problem of if you did develop it what would you do with it? and what would the revenue source be?
Finally it's only 480 exacts but it does have 3600 phrases.
All in all I personally don't think it holds much value - but like I said at the start it's a bit of a weird one and there might be some people out there, maybe those in the internet marketing industry, would be willing to part with a couple of dollars to do something with it.
My valuation - $XX
I agree that low $XXX could be achievable, but you could be sitting with the domain for quite awhile waiting for the right buyer...That's pretty nice appraisal of the domain but I'd add another X onto the value personally. Low-Mid $XXX