I hate comments like this. This is Hacker News, we are highly tech educated and wealthy on average. I specced a 71 TB usable array that can survive losing 3 of 8 drives.
$2000. (shucked drives, but this includes the server and ECC)
If the data is invaluable, throw down a couple of these at homes of friends and family.
I have 10 x 20 TiB volumes, software RAID6, across multiple storage arrays. I wrote my comment from experience.
I still don't consider it "cheap" even though I make a good chunk of change like many on this website, but I think this is because I think in terms of what my friends & family could afford.
$2000. (shucked drives, but this includes the server and ECC)
If the data is invaluable, throw down a couple of these at homes of friends and family.