I'm in Canada, so please excuse the pathetic prices in CAD:
I priced a similar build for a custom PC workstation, and things don't look great for the PC.
https://www.apple.com/ca/shop/buy-mac/imac-pro
$6300 for the base spec.
https://ca.pcpartpicker.com/list/RxvZgL
$8600 for the PC. (Plus, no Thunderbolt, nasty-ass case, no single case etc etc)