For example, what if the choice is between spending more money on your current kids (like by signing them up for cryonics), and having more kids? By giving kid 1 immortality, you snuff out kid 2's chance at life. There are more life or not-life tradeoffs going on here than merely cryonics.

Maybe there are better examples out there, but this isn't very convincing to me.

The limiting factor on the number of kids that people have very rarely seems to be money, despite what some people will say. Actions speak louder than words, and the poor have more kids than the rich.

And if cryonics is a problem because it makes people have fewer kids (which remains to be seen), it's pretty low on the list of things that produce that effect (f.ex. cheap birth control, careers, and the desire for a social life have certainly "snuffed out" many more potential kids than cryonics ever did (if any)).

I'm still a few million in net worth away from thinking cryonics is worth the cost.

How do you figure that?

Are you aware that cryonics paid for via life insurance usually costs a few hundreds a year for someone your age, and probably less for a young child? You've probably played bigger poker hands than that. If money's a limiting factor, it should be easy to trim that amount from the fat somewhere else in the budget.