I don't want to0 be a net.au-basher - I've got hundreds of them myself!
However i do think they are worth a fraction of the com.au equivalent. Remember jobs.net.au sold for $4,500 and previous sales (however thin on the ground) are always the best way to gauge a product value.
Personally I'd rank jobs.net.au as a slightly better domain than loan.net.au.
As is: $3,000
In 6 mths when industry booming: $5,000*
Moderately developed & gaining some limited search traffic: $5,000
*let's hope!