1

Fiji is the cheapest.
Vanuatu is one of the more expensive ones.
NZ is more expensive than Fiji, though of course cheaper than AU.

2

South East asia, especially some of the places you've been to, are some of the cheapest in the world to travel to/around. The pacific islands are more expensive.

New Zealand is more expensive than the islands with a similar airfare price.

Fiji is simply stunning and has the most tourist infrastucture. My personal fave for a relaxing holiday. You can start off in Nadi (as that's where you come in to), then follow your nose from there.

http://www.amazing-fiji-vacations.com/Nadi-Fiji.html

Vanuatu is beautfiul when you get out into the rural areas, although I was there 12 years ago. They drive on the right hand side of the road which freaked me out.

Tonga has the least tourist infrastucture, hence more adventure and easier to experience a real culture. I'm half tongan myself.

http://www.thekingdomoftonga.com/

All would be similar prices. Those are the places I've been to.

Enjoy.

3

There are some good deals advertised to both Fiji and Vanuatu, but they are generally for all-inclusive resorts.

4

tHanks everyone! Fiji ...I havent think about it...

5

I'm wondering if you have ever been anywhere near the Gold Coast (the Australian one, that is). There is a lot more there than all-inclusive resorts and beaches. None of the beaches are reserved for a particular resort, for example, and there are miles of coast, as well as dramatic hinterland.