Originally Posted by Supersonic Swinger

One option would be to:

1. Buy LAX-NRT return on DL

2. In conjunction with that ticket, buy a SkyTeam Asia Pass (http://www.skyteam.com/about/products/asia.html) with three coupons which you would use for Osaka-Seoul on Korean Air, Seoul-Shanghai on Korean, and then Singapore-Tokyo on DL (work with me here, although you'd have to check that is permitted under the Pass rules).

3. The rest of your flights are suited to the LCCs which fly around the region:
- Shanghai - Hong Kong - Hong Kong Airlines
- Hong Kong - Manila - Hong Kong Airlines or Cebu Pacific
- Manila - Ho Chi Minh - Cebu Pacific
- Ho Chi Minh - Bangkok - Air Asia
- Bangkok - Singapore - Air Asia, Jetstar or Tiger Airways
- Singapore - Denpasar - Air Asia, Jetstar or Tiger Airways
- Denpasar - Cairns - Jetstar
- Melbourne - Auckland - Jetstar
- Auckland - Singapore - Jetstar (and from here you'd pick up your last coupon on the Asia Pass to get you back to Tokyo for the return leg to LAX).

I don't know what the total cost would be, but most of the intra-Asia legs on the LCCs you can pick up for as little as USD $50 if you're booking now for travel much later in the year. You can probably get the total cost of your trip below $4,000.