I want to optimize for lowest cost.

I would prefer to use a tool like rsync (and not an inflexible closed source GUI). So, things like Box don't appeal to me.

I'm doing this in case of catastrophic failure to my HD. It is a risk, of course, but I would prefer to pay less for a service that might "only be 90%" as reliable. I don't need 5 9s.

I see a variety of services, the best of which seem to be rsync.net which is priced at minimum of 700 GB for 1.5 cents a GB, so about $15/mo (https://www.rsync.net/pricing.html)

I could run my own VM on Vultr and can't do better than that AFAICT.

I see services like pCloud which have a *lifetime* cost of $199 for 500B (https://www.pcloud.com/cloud-storage-pricing-plans.html?peri...). That seems interesting, and I expect in five years they will say "Sorry, we are out of business!" I'm ok with that risk and will likely plan for that.

But, are there other options to consider? Is there a sweet spot for storage if I almost never need to put more files, can tolerate slow retrieval, and am OK with a discount because the company will probably go out of business?

I could just buy a used desktop off Craigslist with a 1TB drive for $200 and pay for the power myself. That's another option, but I wonder if there is some reason I can find a cheaper option.