Ballyheck: if you want a rundown of L1011 economics vs more 'modern' aircraft, check out the following figures from the US DOT:
http://www.celticairways.com/L1011econ.html
As you can see, the longbody L1011 250 is streets ahead of everything else!
This is due to:
1) Much lower capital costs: you can buy every L1011 in existence for the cost of a single B777!
2) The argument about 2 vs 3 flight deck crews is an interesting one... with an FE, you can fly much longer without additional crew members (which gets very expensive in the case of 2 crew ops).
3) Maintenance costs are lower for the L1011: manhour requirements are higher and parts are a lot cheaper. 'Modern' aircraft require lower manhours spent on them (within the first few years of life); that goes up steeply thereafter and the parts are very, very expensive!!
4) Fuel burn: the RB211 524B4Is burn 15 to 20% less than a CF50C2.
5) From the pax point of view, an L1011 offers a much smoother ride; better cabin comfort through the renewal of cabin air every 3 minutes ('modern' aircraft recirculate air for the whole flight); and the cabins are usually pressurised to a lower level.
As for going for twins rather than trijets, the pax prefer to have as many engines as possible and don't forget either that ETOPS certification has to be earned for new carriers.
Finally, as for carriers in small markets: what about the success (at least untill they got into a p!ssing match with Austrian Airlines) of Lauda Air??
