> Do you look at specific data points to understand if the asset is overvalued or a scam?
Well yes. What you do is calculate the expectation of the future cashflows and PV them.
If there aren't any future cashflows then the fair price is zero and anything else is overvalued. That doesn't mean you shouldn't buy it but you should treat it like any other form of gambling.
If the asset creator won't release any quantifiable information about the future cashflows then the correct response is to assume it's a scam until they do.
That leaves the cases where there are quantifiable cashflows. Some smart contracts fall in this category. What you do then is analyse said cashflows and decide whether the price is justified.