ditzy, no, not exactly. Your example is not comparing apples with apples?
If you give 76 folk to a 146-200 and fly them over a 300nm sector, and give a similar 76 folk to a HGW 717 and fly them over the same sector, you get a result that perhaps favours the 14, until a Dash 8-400 turns up to have a go.
If put a full pax load in each of the 146 and 717, I suspect it would be close, perhaps in the 717's favour
If you change the sector length, to 900nm, maybe the 717 wins
If you put alt requirements on the destination and a suitable is another hour away, maybe the 146 wins it back.
If you make the sector 600nm and all over open water, maybe the four engine airplane wins.
If a given route is, say, a 70 seat route 14 x a week as determined from travel stats and load forecasts, then which is cheaper? A 76 seat aircraft burning 1900 kg/hr, two 'contractor' tech and three cabin crew, lower per hour/per day lease, higher per hour maintenance, lower MTOW therefore lower enroute + movement charges, or a 90 seater burning less per hour, two plus three 'in the QF system now' crew, higher per hour/per day lease, lower per hour maintenance, higher MTOW and thus higher enroute + movement charges......
Or would we be better going 7x weekly in a hand-me-down 737-400, completely amortized, no J class? Would that suit the travel needs of the market segment?
Hell, I don't know!!!
I don't have all the data!
Thats why I think Kym-me-lads confident assertions and rantings are a complete waste of breath.