Those engines exist today, even with the weight of the main gearbox the transfer of energy is what brings economy to the table.
It's just a few bucks on the reserve for time life components
As an operator the expenses are
Fuel
Insurance
crew
aircraft spares
Fuel - bulk sales, and supplying the locals reduces costs
Insurance - fleet policies and training requirements reduce costs - even changing aircraft types-
crew- hire the minimum to get the job done, "Outside Contractor" VS Employee
aircraft spares - Become a dealership - fleet training, discounted spares, sales, fleet rates through manufacture, direct support, advertising.
Poor Djinn was having issues