Theme Club : Your ideas welcome !

I am planning to launch a theme club, where people will be able to become a member for an annual fee and download the themes that I release for the club.

I would like to get your views on this, before I go further.

How much I should charge as a membership fee for an year? How do you like the licensing terms for those club themes? Should it still require a link back from the footer?

I am planning to give one new theme every month for the club members.

Please pour in your 2 cents.