I think Fiji is probably the most sensible option. There was a family on here about 18 months ago who said that they had obtained an all-inclusive holiday in Fiji for $5,000 AUD for 2 weeks for all 4 of them, which was amazingly good value, I thought.
If you go to NZ, the only DIAC office that deals with visas is in Auckland, I think. Auckland Harbour is said to be stunning and absolute magic for anyone who likes sailing, but that is not much cop if one's own hobby is golf!
The other thing to bear in mind is the travelling in the country concerned. For example, Malaysia is lovely (I was born and brought up there.) However I would not welcome a "holiday" spent on top of the Aussie Embassy in KL! The good beaches are many miles away from KL, which is pretty scruffy, hot and crowded in my opinion. Similarly, Phuket is miles away from Bangkok and Bangkok is like KL - hot, crowded and scruffy imho! You don't have to go to the Aussie Embassy every day but it is worth considering where it is in relation to where you want to holiday, I reckon.
I know some people who validated their visa via taking a holiday in Hong Kong. I think that would be a very interesting place to visit though I have never been there so I don't know whether I just have romantic ideas about HK rather than realistic ones!