The script is full of bugs -
1- Students data gets duplicated, if we create student in one school, it automatically gets added to other school.
2- Even if i remove the permission from a teacher to add marks, he is able to add marks of students.
3- Email SMTP setup not working.
4- We cannot even take attendance of students.
5- Departments gets duplicated for every school.
6- When I add class routine, the data chart is not showing for class routine.
7- Syllabus data not showing.
There are many more.

How can you sell an incomplete script?