I've got a handful of 4-bay Mediasonic Proboxes, they're about as barebones of a JBOD enclosure as you can get and run about $110 each unless they're on sale. I have stuffed these things with over 40TB of drives and they've worked solidly for many years.

They typically present as 4 USB connected external drives, which you can softraid into whatever. They also support eSATA. At one point I had 3 of these plugged into a spare intel NUC and used it as a NAS running first Windows, then Ubuntu, then unRAID over about 5 years. It wasn't blazing fast, but got the job done for home use.

I love seeing these cheap builds like this. IMHO NAS boxes are way overpriced, and underpowered. I had multiples the performance and capability piecemeal hacking together my old setup than buying the all-in-one systems that will lose vendor coverage in 2 years.