I'm not sure I understand completely, but let me walk you through real quick, and let's go from there.
So you have a Membership Options Page ( with your PayPal Buttons ), and you configure that Page ( so s2Member knows about it ), under: s2Member -> General Options -> Membership Options Page.
The PayPal Button on that Membership Options Page, is configured for Specific Post/Page Access. In other words, you're protecting a Specific Post/Page, using s2Member -> General Options -> Specific Post/Page Access Restrictions.
Example: If you are selling Specific Post/Page Access to Post ID# 121, you would just type 121 into s2Member -> General Options -> Specific Post/Page Access field. Custom Post Types are fine by the way. Custom Post Types were introduced in WP 3.0+, and s2Member's restrictions are compatible with this.
Now, when a public visitor ( who is NOT logged into the site as an Admin ), tries to access Post ID #121, s2Member will automatically redirect them to your Membership Options Page, which should contain your PayPal Button(s). I gather you've created a branch "Magazine" Page that is linked to from your Membership Options Page. That's fine as well. The Membership Options Page does not absolutely have to be the page that contains your PayPal Buttons, but it should at least provide links to the Page(s) that do. Just be sure, that Posts/Pages containing PayPal Buttons, are NEVER protected from public access. Public visitors need to have access to these PayPal Buttons, so they can click them to complete a transaction that grants them access.
*Tip* make sure you're NOT logged into the site as the Admin whenever you test access restrictions.Statistics: Posted by Jason Caldwell — July 7th, 2010, 7:25 pm
]]>