I just did a massive first cut (chop might be more appropriate) of uc_roles to create a uc_nodes module. I have uploaded it, with a warning that it is NOT production ready by a long shot. It is more of a plaything right now

The granting of roles, and the publishing of nodes are conceptually similar. I am using a derivative of the method in http://www.ubercart.org/forum/support/3450/pay_publish_using_workflow_ng to put the nid of the node to publish into the module. It is a bit of a kludge, so I put the module up for ridicule to see if anyone had any more elegant methods of linking it in. uc_roles is a good, functional module. I think is is an excellent starting point for paid node publication.