But the scenario I want is:
See teaser with buy-now button – click buy-now button – redirect to that specific post = read full post.
A teaser is possible through WordPress® excerpts. Most WordPress® themes will provide an excerpt of the content in one form or another. If your theme does not, you can always customize a template and use the_excerpt()
template tag to get this information. See: http://codex.wordpress.org/Function_Reference/the_excerpt
You may also want to look over this KB article that discusses Simple Shortcode Conditionals, which allows you to protect parts of your content. These cannot be used with Specific Post/Page Access, only with Membership Level Access. However, there is more than one way to sell access to a Post/Page. Specific Post/Page Access is one way (more limited, because there is no user account associated with the purchase); whereas a Member (e.g. a User) will make things a bit easier to deal with all the way around.
Please see: Knowledge Base » s2Member® Roles/Capabilities
See also: Knowledge Base » Simple Shortcode Conditionals
See also: Dashboard -› s2Member® -› Restriction Options -› Post Access Restrictions
See also: Dashboard -› s2Member® -› Restriction Options -› Page Access Restrictions
See also: s2Member® » Video Tutorials