What nickel is worth $400?

I'm curious, what kind of nickel are we talking about here? Is this a misprint or a special, collectible version? As far as I know, a standard US nickel, worth five cents, is far from being valued at $400. Are we perhaps discussing a rare coin with a special minting or historical significance? If so, could you provide more context or details about this particular nickel to help me understand its unique value?