Learners are smoking dagga before they go to class in the morning. They are high and cause major problems in class. Dagga then leads to stronger drugs.

Making it free isn't going to stop them, learners from using it.  Look at Colorado, they have the same problem with the under 18's using it.

Still will not allow it, under age learners will get exposed.

No.no.no.no. Children don't have the ability to see what damage it can do to their developing brains.  These are adult things. Parents aren't home to monitor what their children are up to because they have to work.  Once they start on dagga what will stop them trying something stronger.  Where will they draw the line.