Return the cost of a given name.
        Returns {'amount': ..., 'units': ...}

def rpc_get_name_cost( self, name, **con_info ):
        """
        Return the cost of a given name.
        Returns {'amount': ..., 'units': ...}
        """
        if not check_name(name):
            return {'error': 'Invalid name or namespace', 'http_status': 400}

        db = get_db_state(self.working_dir)
        ret = get_name_cost( db, name )
        db.close()

        if ret is None:
            return {"error": "Unknown/invalid namespace", 'http_status': 404}

        return self.success_response(ret)