The 291 was based on 744 in Wt ( 70 Business class seats) configuration i.e.
First Class: 14 Flat bed sleeping pods
Club World Class: 70 Flat bed seats More Info
World Traveler Plus Class: 30 seats with 2 more inches of recline than standard
World Traveler Class: 177 seats with foot rests and neck supports
Perhaps a more usual configuration is the 52 Business class seats layout? 329 total.
First Class: 14 Flat bed sleeping pods
Club World Class: 52 Flat bed seats
World Traveler Plus Class: 36 seats with 2 more inches of recline than standard
World Traveler Class: 227 seats
A per seat analysis is far too simplistic and was only meant to illustrate the point ,which you kindly acknowledge, and I agree that apples with apples will only give the true picture.
Assuming the same crew numbers for the 52 Bus. config. this would reduce the differential per seat to £15 - a number probably quite easily absorbed in ticket prices. Remembers also that BA can cite efficeinces of scale in some areas that make them more competitive that their nearest rivals. However, although this may be true they will need to work hard to maintain that advantage.