Originally Posted by
tdracer
They did stretch the 757 - the 757-300. You may not be familiar with it because it was a big flop (55 built - 5% of total 757 production). The main problem with the 757 is that it was relatively expensive to build - when the 737NG came along it cost little more than half as much, and aside from long range it could do pretty much anything the 757-200 could.
That is interesting. Why was the 757 such much more expensive to build? Didn't it use the same fuselage cross section that the 707, 727, 737 all shared? If it really was that much more expensive to build, wouldn't that have been true of the A310 and A320 also?