To be able to define prices of tickets to the center we will go to:

Customers → General Rates → Vouchers → Access Vouchers

Once inside the access bonus window, we will have the list of all the bonds we have, if we want to modify or define prices of one of those bonds click on the "Edit" button, as shown in the image provided.

Within the bonus tab, we will go to the Prices option on the left menu, and click on the "Edit" button.

From here, we can see an Amount box, we will fill it with the amount we want.