Built-in virtualization and docker. It's $500 at Newegg.
https://www.synology.com/en-us/products/DS420+#specs
They make bigger ones, of course.
On the other hand, I'd wager you can look at what chipsets they chose, and cobble the same thing together for less (maybe even with 8gb).
I decided I didn't want my data backup to be a hobby, so I hold my nose and use their stuff.
It's fine, and it has some nice stuff like let's encrypt reverse https proxies, it emails every time the power or network drops, etc, etc.
Built-in virtualization and docker. It's $500 at Newegg.
https://www.synology.com/en-us/products/DS420+#specs
They make bigger ones, of course.