Check rclone s3 backend provider list, You might find something useful and cost efficient there.

I use Wasabi storage which is more expensive as they have a minimum space allotment but because my servers are in Aus I had issues with backblaze b2 storage and the latency. (I was dealing with 200-300ms in network latency AU -> US + the time that backblaze takes to store the data).
At that time lemmy/pictrs was not as optimised as it is now so it's much better now.

Backblaze comes out WAY cheaper per-month if you have servers in us/eu, as close to their regions as possible, but they also charge you for API.

As part of an Object Storage / cdn remember you also might have to pay for egress charges as well. Cloudflare is part of the "Bandwidth Alliance" but that isn't applicable here as pictrs needs to present the images via its own domain, (such as cdn.reddthat.com). So you'll still want a CDN infront which will mean you will only pay once for the egress instead of everytime everyone loads it.

• Minio's free tier is a host-it-yourself. Where as their paid tier are for actual storage hosters, they have a minimum of 100TB/month @ $10/TB.
• B2 has no minimum, and egress + hosting of 20GB cost me... ($0.29)
  • Note: They still havn't billed me because I havn't passed the $1 mark yet!
• Wasabi (my current choice) is $7/TB (AU, US is $6/TB iirc) with a minimum of 1TB/month with out egress or api charges

Reddthat has... looks up 150GB of object storage now.

I would recommend B2 if you are starting out and are in US/EU. Wasabi in all other regions and have a CDN infront. (and don't mind burning a little cash for peace of mind)