Hi Steph,
Rents start at about $700 a month in and around Port Vila. Do you want to live in or out of town?. Plenty of "to let" ads in the papers which you can subscribe to online (vanuatu daily post and the independent). You will pay a higher price through a real estate agent. Cars are VERY expensive here, the cheapest I have ever seen was $5000 aus (yes really). Electricity is probably the most expensive in the world at about 70 cents kW/hour. Food can be very cheap if you buy at the markets.
Cheers,
Nick.