[UltraSane]

The cheapest option is to get a SAS pcie card and a new drive like https://www.ebay.com/itm/198052084090 or try a much cheaper used drive.

LTO drives are expensive but they are very well designed and it is the most reliable portable storage format available. Full LTO tapes in a good fire rated safe really provide a fantastic sense of security. The cost of the drive is amortized over the total bytes you store.

[ted_dunning]

Those tapes in a fire rated safe give a sense of security before the fire.

After the fire, it is likely that the tapes and the papers in the safe are a pile of ash. Fire-rated safes often don't survive fires especially if you live in wildfire country.

[UltraSane]

I mean a UL 72 Class 125 rated safe or file cabinet with a 2-hour fire endurance rating