There's not a great reason to make such a claim, unless you are interested in proving a point afterwards. Instead, it's valid to believe "Bitcoin's price today

There's not a great reason to make such a claim, unless you are interested in proving a point afterwards. Instead, it's valid to believe "Bitcoin's price today is higher than its intrinsic value" and take action on that claim by not buying Bitcoin. You may not be forwarding the rational discourse on Bitcoin's price and value, but you are still "putting your money where your mouth is."