First of all, I'd like to say I never log in to read posts, which I do quiet often. So I am sure I am messing up your calculations.
I voted for paying around $25 a year, like a magazine subscription. But a one time membership fee may be a nicer idea, if not too expensive, or an option to either.
My writing skills are not the best and I have received a few emails suggesting to watch my spelling. I guess that is one of the reasons I don