Non -profit priceing
We have a Nonprofit Partnership Program that you can apply for, which gives free (unsupported) versions of Events Calendar Pro and Event Tickets Plus to approved organizations. These two plugins would give you the ability to create recurring events and add tickets to events to be able to track attendees.
However, with recurring events, you can add tickets to the series as a whole, but not to individual dates in the series. We’re working on expanding support for tickets on recurring events, but I wanted to point this out since it sounds like you’re planning to add tickets to recurring events.
Please let me know if you have any other questions!