The IBM PC in 1981 cost $4,500 to $8,500 in today's money. The original Mac would cost $6,000 if released today. Computers have become a great deal cheaper in the ensuing decades.
I'd say it's now $3,750 for the whole setup.
$3,000 for the tower/laptop plus docking station [1] [2], $650 for dual monitors [3] [4], and $100 for peripherals [5] [6] [7].
And that's with Amazon + non-Mac.
[1] https://www.amazon.com/ThinkPad-20ER002KUS-Windows-Professio...
[2] https://www.amazon.com/Lenovo-ThinkPad-Docking-40AJ0135US-Ge...
[3] https://www.amazon.com/Dell-27-Inch-LED-Lit-Monitor-S2719DGF...
[4] https://www.amazon.com/WALI-Standing-Adjustable-Capacity-MF0...
[5] https://www.amazon.com/CORSAIR-K55-RGB-Gaming-Keyboard/dp/B0...
[6] https://www.amazon.com/Logitech-Lag-Free-Wireless-Gaming-Mou...
[7] https://www.amazon.com/SteelSeries-QcK-Cloth-Gaming-Mouse/dp...
Windows is fantastically supported: Microsoft Office, Adobe suite, AAA games, Active Directory, databases, browser and browser plugins, and a thousand others.
Don't get the most expensive RAM or CPU, you lose 10% real performance but you halve your budget.
Today, a Rasbpi costs $5.
Holy freakin' cow.
When I was in college in the mid 2000s my senior project needed a single board computer. We spent $500 on a small PC104 board with a 100MHz National Instruments Geode (x86 compatible) process. That didn't include any RAM or storage. I really wish the Raspberry PI would have been available back then. Especially the Raspberry PI ecosystem, makes interfacing with stuff so much easier. We interfaced a small LCD I found at a surplus shop and it took us weeks to get it working. No you can buy a touch screen LCD for $30 and there are libraries to get it working in about 20 minutes.
By the way, it turns out people think "automation is replacing jobs in manufacturing" because they've misread the data showing them just how much cheaper computers have gotten since then, and therefore how much more computer one factory employee can make.