Backblaze storage is around $6/TB/mo last I checked

For free, no. For cheap, that depends on what "cheap" means to you.

Define "cheap."

Your own RPi and a 1TB micro USB

Get two, keep in separate locations

Y'all need to stop calling Don stupid for asking these kind of easily searched questions. Don smart as hell and got you puds acting like you Don's personal free ChatGPT smh

Dropbox will sell you 2TB of easily-accessed highly-reliable storage for like $10/month.

You can''t because 1TB of storage forever isn't free for them why would it be free for you?

Basically what you want is all files you own should be on more than one drive and computer. Not just raid where the raid array can be damaged or the file overwritten by a careless mistake.

Basically my local files are incrementally synced daily from my computers -> a single board computer with 2 3.5" slots and a big ass drive with zfs. Because ZFS/BTRFS support incremental syncs it normally takes 1-3 minutes daily to send changed files per computer. ZFS also knows when its own data is corrupt and if I find any I can resync known good data from the known good copy.

If the big ass drive dies all the data is on the other machines and I can just replace it and resync.

If the big ass drive isn't big enough or gets old I put a second drive in the other slot and sync A->B and get rid of or repurpose the other drive.

If I want greater reliability I can add a second big ass drive in mirror mode.

If I want even greater reliability I can buy a second such setup and put it another parties house.

If I'm worried about the drive getting lost/stolen encryption makes it so nobody at another address can read shit and I can still do incremental syncs.

This of course isn't free because why the fuck would it be but you can do a ton with just a single machine and drive

https://www.hardkernel.com/shop/odroid-hc4/

https://www.newegg.com/seagate-ironwolf-st4000vn006-4tb-hard-drive-for-nas-systems-5400-rpm/p/N82E16822185030?Item=N82E16822185030&cm_sp=SP-_-2849731-_-0-_-6-_-22-185-030-_-4TB+hard+drive-_-4tb|drive|hard-_-4

$250 Presumably good for 6-10 years or as little as $25 a year 4x as much storage as specified

I'm uploading my encrypted backups to backblaze

https://www.hetzner.com/storage/storage-box/

Local is the only reliant option.

AFAIK cheapest is hetzner storage box (if you're over 600GB and under 1TB) Only problem you can't increase a bit, you need to double storage and cost. For more granular or expecting to pass 1TB soon, Backblaze B2 or Wasabi.

No

google drive I guess?