Personally I just find it easier to push everything to the cloud and not deal with RAIDZ and failing disk drives. Maybe I’m just old.
Upfront storage = $1800
Power consumption (for the entire server) = $20/month
If we bundle storage into the first year’s cost, it comes out to about $2000.
On the other hand, if you use Backblaze B2, storage alone would cost $3000 per year. If you’re downloading content regularly (media), it adds up pretty damn quickly.
I've considered building a NAS for years but I don't know why I just don't do it. Maybe its just the fear of the storage noise which increases a lot on high capacity drives.
To be honest, the noise isn’t too bad with a good case. I use a Define R5, but I hear the Meshify also has great noise suppression.
Never hurts to keep even a USB key of your most essential files and rotate every 5 years. All cloud storage providers have a single point of failure, which is the organisation that runs them acting in obtuse ways. This won't matter the vast majority of the time, but most people have data they care about enough that they shouldn't be trusting just one company to store it. Doesn't need to contain much, maybe family photos, recovery keys, things of that sort.
I also keep a little bit of cash on hand, not much, but history is full of tales of institutions reliably offering essential services until one day they don't, withdrawals are frozen, and people realise that they're screwed.
Also while the cloud is a great value for giving you geo-redundant internet accessible well secured data at a bargain price when you need maybe ~2TB which is more than most people will ever need, once you get up to around ~200TB both the cost and the speed of accessing cloud data gets to be a problem.