Good evening Dan and welcome to the Events Calendar forum!
Thank you for your interest in our products and we’ll be glad to answer your question.
is the pricing for the calendar Pro a one time fee?
That’s a great question. The answer is: it’s up to you.
What I mean by that is that this fee will provide you with 1 year of updates and support.
If at the end of that year you still want to continue using the Events Calendar Pro, you can.
However, we cannot guarantee that it will be compatible with future versions of the Events Calendar or with future versions of WordPress. Furthermore, you will no longer have access to premium support.
Let me know if that helps.
Have a great day!
Geoff B.