Hi Len,
Thanks for getting in touch — these are great questions!
You can absolutely continue to use the plugins after the license has expired. The only thing you lose access to is future plugin updates and access to our premium support forums that are hosted on this site.
I totally understand that the price point can be tough on some budgets. That said, we love working with nonprofits and actually have a nonprofit program I’d encourage you to look at. If accepted, we’d be happy to grant your organization with a free license for either Events Calendar PRO or Event Tickets Plus.
Does this help answer your question? Please let me know.:)
Cheers!
Geoff