that stuff was $150-200 delivered if you buy from taobao.com.
people also need to realize that dual e5-2670v1 has a cinebench score of 2,000, that is just slightly highly than a single ryzen 1800x.
I checked prices for sourcing my own hardware on the same platform, but it would have been a lot more expensive. The problem here in Europe is there is less second hand enterprise hardware available (if I remember correctly, a compatible motherboard alone would have been ~€200, and the RAM was about the same) and importing something from outside Europe means you need to pay customs fees, which in my country adds ~30% to the price.
https://hardwareisboring.blogspot.com/2016/06/hp-z440.htm
And yes, completely silent. Only hear the GPU (upgraded to 1070gtx) when playing demanding games.
Last year I picked up a Dell T3600 with a Xeon E5-2670 (V1 - 8C/16T) and 32GB ECC RAM for €400 delivered. It's not completely silent (maybe HP are better in that regard based on comments here?), but it doesn't make much noise - at least compared to what you'd expect from the power it gives.
I now work from home, and having previously primarily used laptops, this thing feels like a beast.