Not sure about that. All prices from Amazon:
Graphics Cards
GTX 1080 - £660
GTX 1070 - £420
GTX 980 - £430
GTX 970 - £210
CPUs
i5-6600K - £220
i5-6400 - £160
i5-4690K - £220
i5-4400 - £160
Motherboards
LGA 1151 Motherboard - Ranging from £50 to £200
LGA 1150 Motherboard - Ranging from £50 to £200
RAM
£16 GB usually about £70
Case, Cooler, PSU, etc not included.
To stay on the cutting edge, you obviously end up spending quite a lot of money... But that's not a like for like comparison. Once you have a decent PC, you can obviously keep it capable of playing newer games, pretty much by upgrading the graphics card and selling the old one. But you can do the same with your console.
The thing is, your initial outlay on a gaming PC is going to be a lot higher than a console. Buying new, an LGA 1150 motherboard, a decent graphics card, a decent CPU and everything else is at least going to cost £500.
Of course you can do slightly crazy things like
buy old server parts to get the max bang for your buck.. but it's not super simple simon.
Im sure otherwise will disagree