Storage in terms of raw bytes really is dirt cheap, but storage in terms of erasure encoded, encrypted, multi-homed, highly-available file systems isn't. Just buying a hard drive isn't going to get you very far. The durability of a file on a cloud service is going to far outstrip that of your local hard drive or even a fancy NAS.

Cloud services outliving my (not so fancy) NAS. So, where's my Webshots account? (since we're talking photos, let's take a photos example. It shouldn't be hard to find an example of a dead web service for any other kind of data, either)

_My_ datastore still exists and proudly provides those files from my redundantly stored, checksummed, auto-repairing local filesystem. No, I don't have an off-site backup. But neither had Webshots once they decided to shut down.

At least you generally get a warning for a cloud service going down. Then it's around as much hassle as a single component of the NAS failing.

I'm not sure what's more likely, a trustworthy-looking service disappearing out of the blue, or a RAIDed NAS being damaged in a way that data is lost.

Since I've never heard of "Webshots" that seems like a bit of cherry picking. Flickr and Smugmug have both been hosting photos continuously for over a decade.

As per Wikipedia (https://en.wikipedia.org/wiki/Webshots):

"By 2004, Webshots was grossing $15M/year, had more than 200,000 paid subscribers, and was the #1 photo sharing site and top 50 media property per ComScore. In the same year, Alexa ranked Webshots the second largest English language privately held Web media property (behind weather.com)."

Other photo-storage sites that are no longer around include Streamload, Kodak Gallery, Nirvanix, Snapjoy and Everpix.

I won't count Twitpics as it was a posting service, not a storage service, but I expect there are a few closures I've missed....

What auto-repairing filesystem do you use?

ZFS

A $500 Dell T20 Xeon has ECC memory for FreeBSD and ZFS, with room for four drives.

Let's pretend for a moment that this is even a good idea. The $500 server you mention has one (1) 1TB hard drive. Let's suppose you add another one for $75. Now you have a total of 1TB of raw space at a capital cost of $600 and unknown operating costs, let's say $160/year in electricity.

1TB of space on Google Drive is only $120/year in opex and zero capex.

True, but 1TB is probably the absolute worst spot on the capacity/price curve for a home server. For 4TB of space on a home server, your opex costs are identical ($160/yr) and your capex costs are only $120 higher. Yet 4TB on Google drive runs $480/yr. Go beyond that, and the cost delta continues to improve. That Dell server takes 4 drives for 12TB of usable space for a total capex of $1,000, and $160/yr in opex, compared to $1,440/yr in opex at Google. You break even in the first year!

There are plenty of places where self-hosting makes sense. 1TB is not one of them, but many other sizes are.

If you are price sensitive, use a Synology NAS, which has a variety of options for lower opex and capex, and mobile apps that can sync photos to your NAS.

Different people put different market values on privacy of data from 3rd-party cloud providers.

In the market segment which includes HP MicroServer and Dell T20, capex and opex can be amortized over other workloads, using virtualization for NAS VM, router VM, desktop VM, etc. People in this segment may have sunk costs in existing hard drives.

Google drive will limit when and how you can get the data out.

it will limit how you can use that space. (file size limit, etc)

it will require spyware apps to be able to upload photos