You can get a ticket from US west coast for about $1500, not sure what the cost would be from different parts of Canada. A clean room with a private hot water bathroom will cost you at least $30/night. Food is cheap if you eat like a local, very expensive if you want western style meals. A lot of guest houses have kitchens you can use if you want to buy food and cook for yourself. Inter-island flights are fairly expensive. If you go, spend some time on Efate which is where you'll fly into and pick one more island if you're on a budget. Kava is dirt cheap, about $1 for about a 6 oz. serving, and you won't need many of those. Follow the locals for the strongest kava at one of the hundreds of nakamals and prepare to be blown away.