Gun cruiser cost-effectiveness depends on mission

Were gun cruisers the most cost-effective naval units?

It depends on the mission, because presence, wartime tasks, and fleet needs impose different cost-effectiveness tests.

There is no universal cost-effectiveness answer. For peacetime presence, a cruiser-like ship can be very economical because it can be seen, visit ports, and represent naval power. Wartime and fleet-combat value depends on what the ship must survive and whom it must fight. Its value differs across imperial policing, surface action, and fleet-support roles.