Hi Justin,
Thanks so much for your interest in our plugin bundles! 🙂 While we don’t offer any built-in mechanisms for upgrading from a single plugin to a bundle or from a smaller bundle to the Ultimate Bundle, we’re happy to manually assist with these types of requests. Feel free to purchase Event Aggregator whenever you’re ready–if you decide that you’d like to make the leap to a bundle after that, simply drop us a quick email with your request via the below form. One of our team members will follow up to continue the conversation right away!
https://theeventscalendar.com/contact/
(Please select the option “Help accessing my account” from the drop-down menu to display the full email form.)
I hope that helps! Thanks again, and please don’t hesitate to follow up if you should have any other questions!