Home Educators using Public Facilities?

I caught "Taught at Home, but Seeking to Join Activities at Public Schools" and also found related "Home School sports".

As much as I am anti-public schools, I see it OK to take advantage of such opportunities. I think that trying to avoid it as much as possible is the right answer but we can't avoid completely the tax supported public "goods."

The question is how much is too much? That, I don't have the answers. (I'm being taxed, so I want to benefit from it to some extent -- I can't afford to be taxed and then try to replace public services with post-tax dollars.)