Fusion is an incredibly energy dense power source, but that does not necessarily make it cheap. e.g Uranium 235 is 3 million times more energy dense than coal

Fusion is an incredibly energy dense power source, but that does not necessarily make it cheap. e.g Uranium 235 is 3 million times more energy dense than coal, but nuclear power is not cheaper. And fusion is much closer in energy density to fission than fission is to coal.