Do a web search for "satogaeri" fares and you should get a decent ticket. For most major gateways you should be able to get fares under $600 for lower seasons. In case you can't find a site, here's a good reference: URL=http://www.iace-usa.com/ticket/index.html]http://www.iace-usa.com/ticket/index.html[/URL] It's high season now, fares are rather expensive at $800-$900.
BTW satogaeri tickets in general have relatively high booking classes, and many are date changeable on the return leg (please check).
Supply is quite abundant; JL/NH/AA/UA/DL/NW/CO fly multiple US-JPNs daily, as well as carriers like RG and TG fly LAX-NRT like every other day.
Good luck.
[This message has been edited by silver (edited 07-06-2000).]