I'd pay $2 per episode, which was basically what I was paying FMU through the annual donation. I loved those premium funpacks, but that wouldn't be necessary. OK, honestly, I would pay double for a funpack.
What about this (and forgive me if this has been suggested in another thread): the live broadcasts remain free, so the random weirdos can find them and call in, and we pay for the podcast downloads? I think that would be the best of both worlds, and I would listen live and download to listen again.