Plus valuations change over time. In 1997, a valuation of $5m for the first Harry Potter book would've seemed excessive and the author would've probably had tro

Plus valuations change over time. In 1997, a valuation of $5m for the first Harry Potter book would've seemed excessive and the author would've probably had trouble paying taxes on it. But even with that valuation, someone could've made billions by snatching it away once Pottermania started (I suppose you could let authors update value on a daily basis but that seems like an insane amount of overhead)