just write their recruitment team and ask that reasonable question. They will then let you know;
"..I can also tell you that for a CP in France, that flies 90 hours in high season, the approximate monthly salary is 10.000 euros.."
This was the pay conditions disclosed by email in October 2017. This is what the Chief Pilot pulls in during high season, and can assure you, that is ALL INCLUSIVE (per diem, sector pay etc.).
Good luck with it. Again - stepping stone, and get out asap, sure, why not.