Earlier quoted context omitted.
$1,000,000 per lb for R&D is steep, but at this stage in the game makes sense. I wonder what the unit price for a break-even 1lb saving would be. Is it worth spending $20,000 to shave off a pound with expensive materials?
About $2600 per pound. Based on this forum thread [1] the marginal cost per pound to fuel efficienciy is about "0.0155 gallons per pound per 1,000 statute miles". Over a 737's life it may fly about 50 million miles [2]. Combining facts one and two results in a fuel consumption per marginal pound of 775 gallons. Current jet fuel prices are about $3.40 per gal [3]. [1] https://www.flyertalk.com/forum/travelbuzz/712294-…
Of course any change to the aircraft has many other downstream implications (ability to source parts for repairs, lifetime of the part, maintenance requirements), but it's cool to think that for an "all else the same" replacement that the bar is still so high.
With the falling costs of advanced materials I do wonder if next gen aircraft will be substantially different.