If you're gong to do all of this in one or two trips, the best deal you can get for long distance travel is a 'Round the World Air Ticket, an RTW. For one fare from $1600 and up, but count on around $3500 for the most flexible you can travel on approximately a dozen air lines, including some of the best, right around the world making stops along the way staying for as long as you want as long long as you travel roughly east or roughly west. The more flexible ones allow you to make flight changes as you go. The cheaper less flexible not so much. Even the cheaper ones can be the same as the average trip to Oz or New Zealand and you can stop in Singapore, Hawaii, South Africa and Frankfurt on route so you're not so fried by the looooooong trip to NZ.
Another great air deal is an island hopper in the South Pacific using Fiji, or similar as a base. For a set price in a set timeframe you can visit as many islkand as your time and schedules will allow as long as you only visit a place once. It's like a Euro Pass in Europe only by air from island to island. From Fiji, it's the easiest/cheapest way to visit one of the most remote islands in the world, Easter Island. The last time I looked at Nandi to Easter Island fares it was $100 and now compare that same fare from Quito Ecuador, $400.
Another great air deal is an island hopper in the South Pacific using Fiji, or similar as a base. For a set price in a set timeframe you can visit as many islkand as your time and schedules will allow as long as you only visit a place once. It's like a Euro Pass in Europe only by air from island to island. From Fiji, it's the easiest/cheapest way to visit one of the most remote islands in the world, Easter Island. The last time I looked at Nandi to Easter Island fares it was $100 and now compare that same fare from Quito Ecuador, $400.