I see a key for PLN 79. How is it different from that for PLN 20? Why illegal? What's illegal in it if it works and undergoes verification and activation on MS servers? I will contact the client, which is exactly what he means because so far I have not had a problem.
Added after 4 [minutes]: According to whom is it illegal to use such wines, since MS itself registers it with the computer's configuration and activates it? Who Decides It Is Illegal?
Added after 1 [hours] 46 [minutes]:
Added after 1 [minutes]: https://support.microsoft.com/en-gb/help/15087/windows-ghorn Added after 5 [minutes]: I just bought a key for a few pounds and activated win 10. Activation and update no problem. I did it

Positive verification. So how is it positive if supposedly wines for PLN 20 are not legal? Someone explain to me?
Why MS servers allow such keys to activate 10 wines? Then the question arises, if everything is ok for MS, who are these keys illegal for?