"OK, the 29K fare is somewhat less, but are you allowing for the fact that you can do something like 70,000 miles on a *ONE4, and that a fair proportion of those miles can be on QF, or QF codeshare or IB or AY or LA?"

It is quite hard to do 70,000 miles in 20 segments (which is the maximum allowed on a OWE). That does require an average flight distance of 3,500 per flight

Dave