A rough price out using new egg/microcenter pricing, substituting a few items where they didn't specify a specific item/brand. I didn't bother trying to figure out what case they used.

Grand total: ~ $41,000

Motherboard https://www.newegg.com/gigabyte-mh53-g40-amd-ryzen-threadrip... $895

CPU https://www.microcenter.com/product/674313/amd-ryzen-threadr... - $3500

Cooler https://www.newegg.com/p/3C6-013W-002G6 $585

RAM https://www.newegg.com/a-tech-256gb/p/1X5-006W-00702 $1600

SSDs https://www.newegg.com/crucial-2tb-t700-nvme/p/N82E168201563... $223 x 4 = $892

GPUs https://www.newegg.com/p/N82E16888892012 - $8295 x 4 = $33,180

Case https://www.newegg.com/fractal-design-atx-full-tower-north-s... $195

Power Supply https://www.newegg.com/thermaltake-toughpower-gf3-series-ps-... - $314