The real cost of the distraction-only-fingerpointing-entertainment-amusement-multimedia chaos dubbed Windows 10 can hardly be estimated by today's dinky standards. From the betas (actually pre-alphas) I expected the worst and - guess what ? - got less. There are people who actually do productive work with their computers.
After a bumpy downgrade from a reasonably stable Windows 7 ( 8 was unusable for working ) to a buggy Windows 10 there was some sort of a menu mixed with unrelated apps cluttering the plain ugly user interface. The new wonderbrowse soon failed to start and edged off the screen.
The only one benefitting from the supposedly free ( as in gratis ) change to Windows 10 is the villain forcing you to give up control of your processes and data. The mighty cloud ( actually fog ) takes care of what used to be private and secure. As an added benefit you will get personalized spam, select malware and a yearly payment plan.