The cheapest way to get a PC is to buy the components yourself and screw them together. It's not as difficult as you might imagine.
A lot of people prefer notebook/laptop computers these days, and there's really no way to build your own. Also - at the bargain end, the cost of building your own computer using components is probably going to be more than the cost of just buying a complete system. The complete system will also come with volume OEM software licenses.
https://lifehacker.com/is-building-a-pc-really-cheaper-than-buying-one-1443171781
In the US a retail copy of Windows 10 Home is $120. My wife bought a cheap refurb Lenovo Thinkpad laptop for about $225. That came complete with a refurb Windows 7 license that I was able to use to reinstall Windows 10 Pro.
Wait, you pay for Windows?! J/K!
It is true, self-build laptops just aren't a reality per se. And of course, they are very desirable (laptops that is). Heck, I don't know what I'd do without mine!
The cheapest way to source components isn't from online retailers, rather from Facebook contacts and, if you're daring, eBay. They should shape up fine