So given the fact of site hosting billing based upon traffic, your cost should see a large decrease, right?
I feel your pain.
I have thought about this situation in depth and honestly, if it isn't economically viable as a free for all with minimal donations and profits from the STORE to cover your lead generation costs, and it isn't economically viable as a pay to participate format, then there are only threeoptions left:
1. You give in to ads and click revenue to cover operations and learn to live with the obnoxious clutter.
2. Sell it.
3. Throw in the towel.
You are honestly torturing yourself here and we all read post after post about it, but we are really powerless to do anything demonstrably constructive about it.
Only you can.
I hope a palatable solution reveals itself to you soon.


