The single-engine or twin-engine criterion is not relevant for evaluating the cost in operation. For example if we compare an F-35 and an F-15 we have two aircraft roughly comparable in weight and thrust. F-35 is single-engine and F-15 is twin-engine, yet it is likely that the operating cost of F-35 is not lower than that of F-15.
A more interesting criterion is the mass: the French DGA studied this subject and determined that, all things being equal, the cost of operation was proportional to the empty weight.
you can compare the M88 fuel consumption with F414. More over a country needs to see it's fuel reserves and other sort of logistics before going for twin or sin eng. of comparing operating cost of f35 with f15/f18 is not right example. Both are different categories.
Not happening. Because if it was to be ordered, would have ordered by now. brining another 164 rafales would take 10 years. INDIA cnt remain without stealth tech for long, so the capital will be invested in either fgfa or amca.Rafale is going to come in more than 200 numbers