At the current level of usage and compute resources it costs about $50000 per year to run the services, if you don't have to pay the humans that help build and run it. We are an open project, if anyone wants to join to learn more about Kubernetes, Jupyter, Ops, Python, Docker you would be very welcome. We hang out on https://gitter.im/jupyterhub/binder and https://github.com/jupyterhub/binder is a meta repository.