Reading some other comments, I think the suggestion is that the overrating was fraudulent. In which case the price is a relevant factor. Mayer was worth some amount of money, a mild overestimate would be human error, but a massive overestimate would be evidence towards a fraud claim (in the sense that the error would demand explanation as unintentional). I don't endorse that on a Mayer-specific level, but I think it's the shape of the argument.
None of which disagrees with you, it's just an interesting note for assessing what a hypothetical fraudulent CEO appointment would look like. Presumably it would factor in price in the sense of "could a reasonable person assess the CEO's worth at this value?"
Fraud isn't a function of magnitude. A $2 fraud and $2 billion fraud are both fraud.
What matters is intent, the concealment of material facts and the victim's harm resulting from the foregoing.