In response to answer 2: how do you account for the risk of storage invalidating stem cells after 60 years, if you've only experienced useful 30 year-old cell lines? Put another way, why would I pay $7,000 if neither you nor I knew if my cells would still be useful to treat disease when I'm 80, assuming I stored them at 20? Do you have a method of propagation in intervals, ex. thaw, expand each set of cells every 10 years, and re-freeze? You mentioned in an above comment[0] that you'd need a clinical trial to have the legal ability, so perhaps not?
We aren't propagating at intervals currently. However, it's something that could be done; batch samples could be set aside for that purpose alone, also, one control sample could be divided and tested every 5 years. It's an interesting question: if I culture my cells after 20 years, then preserve them for 20 more, is the viability higher than 40 years of preservation alone?
[0]: https://news.ycombinator.com/item?id=15386671