IME price difference is not such a big deal when there is just one traveller. €12-20 is not going to make much difference, parking in one airport Vs travelling to/from that airport has a much higher weighting, as do timings. So at the end of the day there may not be much in it. When one is travelling with a family of 4, any savings will quickly mount up and become much harder to ignore. More inconvenient travel times or travel to/from the airport are harder to justify, especially in times like these.
All of that said, one airline being cheaper than another, on a given route, on a given day is not indicative of anything. As always, it pays to shop around.