Charge two dust per turn per ship, modified by....



Support only ships (might need redesign of starting scout ships) cost only one dust per turn to maintain regardless of map location.



Each colony module past the first increases maintenance cost by one per turn



Combat ships outside of an empire's influence area and or attacking an opposing factions system cost double. Combat ships are defined as any ship with a weapon system or invasion module.



Starting position in game would incur a cost of 5 dust per turn with as is design of scout, 2 if no weapons installed.