If it is that valuable, you should consider multiple backups...kept at multiple locations. Your home, a safe deposit box, a trusted relative, etc.Well, yes, because the data is so precious / important that actually it cannot be assessed.
A bit more, I think, from may be 220 $ for 10 TB. I would need some of them.
So you may need 30 TB or more, with a suitable rotation plan among them all.