If it was going to the Sandbox you would know it, because you would have to login to Developer Central before you could 'pay'.
The Sandbox should allow you to go through the complete cycle, since it does send back Internet Payment Notifications (IPN) when payemts are complete. In effect it should be invisible to your site whether your are using the Sandbox or not.
This is speaking from my work on the payments side the the Core DNN Events module. I am not familiar with payments mechanism within the Subscriptions module, but assume it should work similarly.
Roger |