Originally Posted by
Sixth Freedom
This may not be the case. Provided that you travel with at least two oneworld airlines then you can travel up to 35,000 miles in economy class for 140k Avios plus all the taxes and surcharges.
BA Avios has a different system if you travel on two non-BA airlines on the same ticket. In general it's considered worse value but there may be arbitrage. It is explained here:
http://www.flyertalk.com/forum/briti...l#post24087985
But if you are taking a lot of stopovers, there's no reason to put everything on one ticket. Buying sector by sector you can use the "normal" system.
I would also say that taxes and fees tend to be pretty low per sector (<£40) if not travelling longhaul on BA.