That's not classical economics, that's asset specific. Try pricing USD or a commodity or literally any other asset that doesn't represent financial investment in a business venture in a discounted cash flow model.
It's going to sound hand wavy, but it is a new asset class with a novel value proposition, so analyzing fundamentals will require assessing novel characteristics.
How do you price a currency on fundamentals? Some of those indicators apply, like supply, yearly monetary inflation, reserves ("hoarding"), and some don't, like stability of the issuing state, but an analog to that would be network security.
How do you price tulips? I'm not going to pretend that there isn't a massive section of demand that is entirely speculative.
As far as a novel approach, you have to gauge potential utility, something there aren't very many analogs to in other asset classes. Can you send it over borders without being molested by various bureaucracies? Is there some guy that is going to change how things work under pressure? IMO the unique fundamentals of a cryptocurrency have to do with censorship resistance, permissionlessness, fungibility, some of the hot buzzwords that people use as selling points are more than buzzwords. And there's no century long history of refining the methodology of doing this, we are figuring out exactly what works and what doesn't, which is a part of the process of price discovery with any new asset class.