I don't think an equivalent PC really costs $7000 USD....
And it comes with Windows. Nobody deserves that.
I'm sure with $4700 more it's possible to get something still better than this new imac pro.. yet with a good cooling system and upgradable at any time.
edit: $2300 INCLUDING 15% taxes
You'll probably can get something with higher performance, but it'll probably also take up more space, generate more heat and make more noise. It'll also demand more time to select the components and assemble it. If you enjoy doing it, OK. If you don't, your time is more expensive than the difference.
I selected a Dell because I want a single phone number to call when something goes wrong.
This is for desktop, for laptops I might still go with apple however.