Additionally, regarding using Google Flights / ITA Matrix, take the results with a grain of salt until you see the fares for yourself on the Airline/OTA's website. Google sometimes shows phantom fare availability or fares that are not bookable (at least for most people).
This is true to many airlines.
I thought I found a good ~£25 fare on Air Seychelles on a domestic flight the other day, turns out it was for Seychelles residents only, and found that the real fare was ~£100 for a 15 minute flight.