I've been considering "de-enterprising" my home storage stack to save power and noise and gain something a bit more modular. Currently I'm running on an old NAS 1U machine that I bought on eBay for about $300, with a raidz2 of 12x 18TB drives. I have yet to find a good way to get nearly that much storage without going enterprise or spending an absolute fortune.
I'm always interested in these DIY NAS builds, but they also feel just an order of magnitude too small to me. How do you store ~100 TB of content with room to grow without a wide NAS? Archiving rarely used stuff out to individual pairs of disks could work, as could running some kind of cluster FS on cheap nodes (tinyminimicro, raspberry pi, framework laptop, etc) with 2 or 4x disks each off USB controllers. So far none of this seems to solve the problem that is solved quite elegantly by the 1U enterprise box... if only you don't look at the power bill.