AlanWade said:
If you are running Windows 10 Home Edition and want to upgrade to Pro you can do it for about £1 English or 14:99 Swedish kroner.
To do this click on Start then Settings.
Now click on Update and Security then on Activation and you will see the option to upgrade.
Click on "Go to Store" and you can buy it for about a £1.
I've just tried clicking Go To Store from an edition of Home, and it now says
"for testing only. Do not purchase"


-windowsstore_proupgrade_20150704.png


This suggests to me that any product key you might obtain this way won't work in the final release.