why the 767-400 is not popular??
 

767-400 is operated by only 2 airlines in America

my question is that
why other airlines is not buying this big bird?

Probably just not enough benfit from equipment commonality to overcome operarational savings over A330 & B777.

on that note, anyone know how the trippler compares with the 764 pricewise?

Yes, both introduced late in the airplane's life cycly, with replacements already identified.

It's interesting, though, that the 764 cockpit is virtually identical to the 744, except for 2 vs 4 throttle levers, etc...

Which. of course begs the question, why the 764, 777 ( all variants) and the 737NGs flightdecks aren't identical with common TRs.

Qantas needed a bird that could make continental North America non-stop with ease and high payload. Plus they also needed to make Buenos Aires non-stop, Johannesburg non-stop all in a fuel efficient high payload aircraft.

Australia is alot further away than the US to Europe and Asia.

Go fly it at MTOW single engine...haha