Hey Chris,
Absolutely! The Events Calendar is a free download and then you can purchase the Community Events plugin to add the functionality that allows users to submit events to your calendar–you can set it to accept events from everyone, or only those who are currently registered on your site.
Will this do the trick for you? It’s also worth mentioning that all our plugins come backed with a full refund within 30-days of purchase, should something not work out the way you had hoped. That should give you some time to play around with things. We also have a tutorial over here that walks through the various settings for Community Events that will give you a good idea of how it works.
Does this help answer your question? Please let me know. 🙂
Cheers!
Geoff