Minimum permission set to enable Manage Contribution Pages?
Administer CiviCRM includes administering Contribution pages. You can create a role for administering the CRM (such as editor) and then actually restrict menu items to that same role so that they don't have easy access to everything else. However, it would be pretty hard to make a contribution page without being able to access nearly all the other settings.  

Managing the contribution pages is a higher function.