Seems liked you are paying a lot to get all the pieces preconfigured.
I just built a Roon ROCK server based on a NUC8i7. All the parts including a 2TB SSD were under $1000 and it took me about 2 hours to assemble and configure.
The only downside of using a NUC is that there is a tiny fan inside which you might be able to hear if you are within a few feet and you have a very quiet room. But I leave my server in my utility room with the router and use a streamer in my audio rig.