Can the text on this page be changed to something like "Please enter your email address and follow the prompts to complete your payment for <Product Name>"?
I believe if the person is paying for a product or membership subscription, it's confusing to say they're invited to join a community. If someone is using the invite link on an external sales page as their pay button, this is even more confusing. It may also just be better to have email address & payment info being asked for on the same screen instead of two different screens.