Originally Posted by
thebigben
Two options IMO: Two ex-EU flights, or an Avios redemption. The RTW tickets are too expensive for that kind of itinerary, they're mostly useful if you have lots of stops to do.
Fair point: to clarify my above - I think a DONE would work out cheapest if one is only willing to do UK-JA-US-UK as the most convenient routing. One probably can save some [and get more TPs if Oneworld] with ex-EU fares if one is willing to do the extra flying. Cash one-ways are likely to be more than a DONE, I would guess - and given that it's the Olympics [rather than the RWC] ex-EU starting points to JA might not be very frequent or cheap due to the fairly widespread demand.