Hi Scott,
We do have a product called Community Events which lets users submit events.
What it doesn’t do, out of the box, is facilitate the selling of space – but it could certainly be a working foundation for a more complete solution tailored to your needs.
Between Community Events and our core plugin, The Events Calendar, there are no shortage of hooks and other customization opportunities so this could definitely be a great platform for you to build on 🙂
I hope that answers your question, but please don’t hesitate to let me know if we can help with anything else.