I'm no stranger to building boxes or running servers, but I've run a couple of different Synology NAS over the past 15 years. My estimate is that if I were to put together my own system, it would probably take several days and cost about the same as if I were to buy Synology. I'm not familiar with building NAS systems specifically, so that might be part of the issue. But saying you can do it in one hour seems like hyperbole.
When I looked into it last, I planned to spend about as much as a Synology, but it would have much more compute, memory and as much storage. I was likely going to run ProxMox as a primary OS, and pass the SATA controller(s) to a TruNAS Scale VM... Alternatively, just run everything in containers under TruNAS directly.
For my backup NAS, I wound up going with a TerraMaster box and loading TruNAS Scale on it.
