In Europe my local national carrier is often cheaper than the rival LoCo, if you can be flexible with dates & times. And therein lies an advantage: the national flies every day and usually 3-4 times. The Loco often flies less than everyday and usually only twice at not very convenient times. It will then depend on how much luggage you take as to the bottom price. The true price is also 'door to door'. So include the cost of travel to/from and any car parking. At a major airport public transport can be cheaper than car parking. Cheap public transport at destination instead of taxi from middle of now where can be cheaper. There's more to it than simple ticket price. To say LoCo is always cheaper than national carrier is a sweeping statement.