If you think living forever is worth money, it's reasonable to sign up for cryonics even if it's unlikely to work, because the other options (being buried in a wooden box or burned to ashes) are considerably less likely to work.

Let's not get Pascalian here. It's reasonable to sign up for cryonics even if it's moderately unlikely to work, but probably not if it's ridiculously unlikely. Opportunity costs matter since some of my values aren't about my own subjective experience.