Howdy @nnyorker,
Ticket sales are the are the primary way to monetize The Events Calendar and Event Tickets at the moment. We also introducedĀ Community TicketsĀ a little while back so that you could monetizeĀ event submissions usingĀ Community EventsĀ by allowing other folks to sell tickets on your site and to split the sales with you.
Charging a fee for listing an event is certainly another way to go. While Community Events does not support that right out of the box, you might want to consider looking into Restrict Content Pro. That would allow you to add a paywall where someone would need to pay in order to access the event submission form, effectively allowing to charge for Community Events submissions.
Does this help answer your question? Please let me know. š
Cheers!
Geoff