You add costs to a class when adding a new class or by editing an existing class.
To edit an existing class, select your name top right, 'hosting', select the class name and select edit class.
Select next, next, so you are on the third page.
Click on the cross next to the price to delete the old cost.
Select 'add a fee'
To change between Class Pack/Bunch and Full Term, click the drop-down menu
To enter the price edit the 'amount' box, after this press the 'Add' button down the bottom.
To add another class click the 'add a fee' button.
Once you have added all the costs, select 'Create Class' on the bottom of the page.