I saw some questions regarding the pay of a HOD in secondary school. In the Singapore education service, your pay commensurates with your qualifications and your pay grade. A HOD in a JC, Secondary or Primary school can be having the same pay as long as the grade is the same. Everyone starts in the GEO1 grade which is the same for all degree holders. You progress up the career ladder in terms of grade and job appointments.

JC, Secondary and Primary are like the different divisions in army.

The pay of 6-8k per month is normal for a HOD considering it is a mangement level job equavalent to a head of department in the army HQ division. As principal is a superscale level job, which is min $10k.pm, thus is is quite normal for a HOD to command such pay.