How do I give one student a different price?

On the student's profile, edit the subscription and fill in Price for this student. Only the owner can do this.

1. Student profile, Subscriptions block, Edit.
2. Enter Price for this student. Leave empty to go back to the type's price.
3. Save. The row shows "own price".

This price replaces the type's price and the family discount. It updates the due dates that have no payment yet and whose amount is the old price; a due date that already has a payment, or whose amount was corrected by hand (Correct the amount), keeps its amount.