PCPartPicker part list:
https://pcpartpicker.com/list/4v7byX
Price breakdown by merchant: https://pcpartpicker.com/list/4v7byX/by_merchant/
CPU: AMD - Athlon X4 845 3.5GHz Quad-Core Processor ($53.13 @ Newegg)
Motherboard: MSI - A68HM-E33 V2 Micro ATX FM2+ Motherboard ($44.99 @ Amazon)
Memory: Patriot - Signature 8GB (2 x 4GB) DDR3-1600 Memory ($49.99 @ Amazon)
Storage: Seagate - Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($42.20 @ Amazon)
Video Card: MSI - GeForce GTX 1050 Ti 4GB Video Card ($164.99 @ B&H)
Case: Rosewill - SCM-01 MicroATX Mini Tower Case ($22.99 @ Amazon)
Power Supply: EVGA - BT 450W 80+ Bronze Certified ATX Power Supply ($9.99 @ B&H)
Total: $388.28
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-09-11 19:43 EDT-0400
That's the cost of building a PC with specs similar to PS4 Pro.
Games are cheaper on PC if you know where to look to find the deals. Smart PC gamers never spend retail price on games while console gamers often have to pay retail on new games.
Also you save the PSN plus fee. AKA the online play Tax that Microsoft introduced with the Xbox 360 and now everyone else is adopting it.
So yes. PC is cheaper. And also it isn't. PC is whatever you want. It can be much more expensive or much cheaper. It all depends on what you want out of the PC.