Enabling the add-on will add an extra price field to the choices in the back-en:
You can choose between 2 options for the extra price type:
- Fixed amount, which is the default and most used way to add a specific price for an option
- Percentage of the product’s price, which will calculate a price relative to the base price entered in the product data.
Additionally if you also use the Form builder add-on, having the Extra price add-on will enable other calculation options:
The calculation value can be used from within a calculation field in a Form layer:
This value will be made available from the calculation field, and will be used only if the choice it is set in is selected.