I bought a second-hand HP Z2 G9 W680 motherboard for less than 100 USD and within last 3 months had gained enough experience to share. Considering all other W680 motherboards cost upwards of USD 500 at this point, this turns out to be a fairly attractive solution to get a modern Intel system with low idle power consumption, PCIe Gen 5, and, most importantly, ECC memory support.
