dreamwatch
Still, 2 or 3 more inches for a £100 would be a no brainer for me.
I suspect the problem is called 'product differentiation' or some such by the kids in marketing.
The problem is that, if they give you that three inches for £150, how do they continue to justify giving someone in the next cabin along an extra nine inches for £1,500?
Obviously I am just picking figures at random but they HAVE to keep the price gap high, in order to keep up the price of the really big seats. If they allow pricing to start sliding backwards, they will be in trouble, especially as they need to raise prices. (On one route I looked at as a possible this year, checking at February and October, the October price was 25% higher and you would expect it to be the other way around.)
I think that the way they are providing the few extra inches for £100/150 is the selling of exit row seats (which has been discussed here a lot). Lastly, American Airlines did a big campaign to throw out rows of seats and expand the leg room. They found it made no difference to sales as the sale is dependent upon the price. They found that people want to pay less and grumble more - and that was two years ago before the Recession.
So I do not see any carrier changing current practice and offering a bit more for a reasonable price.