Storage volumes can be much cheaper. For instance, Backblaze B2 will run you around $6/TB/mo, IIRC. And some providers (usually the smaller ones) have discounts for bulk purchases (e.g. a year). Many self hosted apps support cloud storage.

Is it possible to use B2 or DO Spaces as storage for Photoprism?

Sort of. It's not natively supported, but you can use something like s3fs-fuse to mount a S3 compatible storage (like B2) locally and use that. I personally went a different route: Set up Nextcloud, point its primary storage to B2, and then mount a Nextcloud folder (using WebDAV) to my filesystem which I configured as primary storage for Photoprism. That setup was pretty slow, but I also had Nextcloud and Photoprism running on the same VPS which additionally was underpowered for even Photoprism alone. I am now using a separate server for Photoprism and performance is much better

PikaPods has much better storage pricing for PhotoPrism.

i don't see any pricing for storage on their site

n/m signed up and you use sliders to get what you need.. looks like its about $15 a month for 1Tb of storage which isn't enough for me.. too bad.

I dropped them an email and they increased the cap to 6TB. I enabled 2TB on my pod and it estimates $20/month.

I built a lower end linux machine out of consumer grade parts in order to self-host this. I think it ended up being $600-800 with 8TB of storage but could be done a lot cheaper. Hard to beat $10/mo though unless your needs extend beyond storage. I ended up using it for a lot more in the end (mealie, wordpress, etc). Something to consider if you the budget and time.

That sounds very expensive for 8TB of storage. I should think you could build a modest NAS for half that. Alternatively, buy two Western Digital My Books to get more space + redundancy.

I didn't want a NAS. I wanted a linux machine to experiment with docker and setup photoprism. I am self-hosting ~20 containers so far. It has 32GB RAM and pretty good CPU to experiment and run different workflows in the containers. I noted it could be done cheaper but that is not my goal. Can always add external storage.

I self host on an old i5 machine w/ 8 GB DDR3 and it works a treat. I back up (300GB) to Backblaze (and another machine on prem) for about $3/mo or so.

My Hetzner server that I rent for 40€/mo has two 4 TB drives.

I don't think they have cheaper servers at the moment, but Digital Ocean seems awfully expensive.