cheapest way to get to Vanuatu from Fiji or NZ

I'm quickly falling in love with the idea of a trip to Vanuatu but my research indicates that getting there is expensive and I'm on a tight budget. I'm going to be in Fiji and New Zealand on my trip so going from there to Vanuatu is probably the best bet.

Does anyone have up to date fare info on Visit South Pacific / Triangle air passes (or other suitable ones)? Or good airlines/flight deals from NZ / Fiji?

Are there any realistic options to get to Vanuatu by boat?

Thanks in advance!

Vanuatu is much closer to Australia than New Zealand, so the cheapest fares are out of Brisbane, Sydney or Nadi.

The cheapest way would be from Fiji, using Air Pacific's Bula fares.
They are advertised on their website.