When a customer is subscribing to a product, the Totals block on the Shopping Cart screen show zero values (see image below)
As explained in this article, the extension does not create an order immediately when a customer subscribes. Therefore, there is no instant payment, and the Subtotal and Grand Total values are "0". The actual fees are represented in the below "breakdown" table, where the customer will see the regular charge amount, the Trial Period amount (if enabled) and the Initial Fee (if enabled).
In fact, this aspect of the extension's behavior has been modeled after the native Magento Recurring Profiles function, which works in a similar way.