It sounds as if I wasn't clear, so let me be more explicit.
I believe the intention is to be able to keep people cryopreserved for an unlimited period.
For this to be so, the alleged one-off cost of keeping them cryopreserved should be such as to sustain that ongoing cost for an unlimited period.
A conservative estimate is that with a given investment you can take 2.5% of it out every year and, if your investments' future performance isn't tragically bad in comparison with historical records, be reasonably confident of never running out.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
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