Where did anybody in this thread say that the entire fusion generation infrastructure was free, cheap or even moderately priced?
All anybody said was the cost of the frigging LITHIUM was insignificant. Then you come in and ask for people to back that up with numbers, because after all, it can't actually cost zero. Well, it's been spelled out for you: A year's worth of a typical household's electricity involves a few cents of lithium.
Now you change the subject and point out that whole fusion generation infrastructure could still be expensive, just like overpriced fission plants. Well, no shit.
But don't sit there with smug superiority, because that's not the silly question you asked in the first place. You asked *specifically* about the cost of the input material.