It's a bad strategy for someone who'll die soon, because they can't get life insurance. Cryonics is cheaper when young and healthy.

Life insurance is more expensive than paying in cash. If that weren't true, no one could make money selling life insurance. Yes it amortizes the cost over time, and amortizes the risk over the population but that does not reduce the cost of it. The opportunity cost of cryo-preservation is the same whether you buy insurance or not.