Everything depends your living style , even though these are average per month ;

Decent 2 BHK QAR will come 4000 to 5000/-

Abu hamour, Mansoora, Al Saad, wakrah, Mushreib, etc are good place to live with family..

E & W bill around QAR 300/-

Internet connection QAR 250/

School Fee & Others = QAR 1000/-

Cost of living is little bit high in Doha while comparing other GCC