Oh the fun of running a popular web forum.

I run one with about the same traffic levels as here, it chews up quite a bit of resources. Though I have the luxury of dedicated servers, it's not really a requirement. A VPS might be an adequate and cost-effective option for Pond Boss.
Shared hosting is a terrible thing to deal with, I feel for you JP.
A subscribers-only forum sounds like a good idea if affordable hosting can't be arranged, though possibly not easy to get going and maintain. Doing that may boost subscriptions enough to more than cover the hosting costs.