Currently Role Scoper couldn't do that because it's not possible to "assign" the anonymous user the ability to read a page which is hidden from logged users.  I could add that ability, but I'm afraid it would be too much of a liability and lead to some clunky solutions that are better handled in other ways.  In the end I think you will be happier with a system that does not force the maintenance of two separate pages for member/non-member.

Maybe the HidePost plugin would help in this situation. You could leave the non-member price always visible, but follow that with [hidepost=level] member price [/hidepost]

Another option might be a dedicated shopping cart plugin like WP E-Commerce (I'd think that some such  solution would enable member / non-member pricing)