Yes, that's basicly the trick.
Sorry, but thats becomes more and more the basic problem.
Even with a perfect aircraft, short flights are bad for business. On the one hand, there are a lot of other means of transport, on the other hand, a lot of costs of a flight accumulate per flight/per cycle and not per flight hour (e.g. landing fees, maintenance costs). The limit of 1500NM is leaving only a small spectrum of ranges, where airlines earn money. Take a look at the BAe146 and the lack of range and the lack of success of this aircraft.
A smaller and very light airframe could be the first step to a more fuel efficient aircraft. But while the whole aviation world is talking about the fuel price, airlines are paying leasing rates (or interests), spendig a lot of money for maintenance, paying fees and give money to the crew.
Saving 500kg fuel from LHR to AMS woud be great, but if the other costs are to high, you can't sell even one Turboliner.
Again, here arrives the weight at the scene. You want to offer a short range aircraft, which is flying thousands of cycles (round about 100.000 cycles in 30 years ?!). And the weight is lower than anything known today. This could work, but the mechanicians would have to change a lot of structural parts during the life cycle. In this case, the maintenance costs would hit the roof.
Take the average structure weight of some comparable modern aircrafts (320/737) and subtract 10%. This would be more serious than scaling up from a very special kind of aircraft like the BAe146.