Yeah I checked out the Mac Pro but at that price I would definitely just go with a PC with at least one (maybe 2) 1080 ti's.
I can't see spending $5,000 on a machine that doesn't absolutely crush 90% of the computers out there.
The computer is going to take a majority of my business budget and I'm fine with that.
I still have to consider the cost of a drone and a couple camera accessories (off camera flash, additional lenses, etc).
$3,500 or so for the computer is what I'm comfortable spending right now considering everything else I have to budget for.
That's why I've been looking at the Alienware Area 51 vs the 5K iMac 27".
Sidenote: I don't know if you heard but the latest Mac OS has support for external GPU's.