I do have to say, $9.99 is a pretty good price for this. But this again reinforces my point: if people really hated the Win10 UI that much, a $10 purchase should be nothing to fix it.
Also, I only looked over the link cursorily, but does this fix the whole Metro interface? That's my big complaint with Win10; when you're on the regular desktop, it isn't much different from Win7. It's when you want to load a new program, or use the Settings, or stuff like that you suddenly find yourself in the purple hell that is the Metro UI. If this Windowblinds program is only letting you skin the desktop stuff and not changing the whole start menu, then it's not really fixing the problem, just making the crappy, clunky Win7 desktop more pleasant to use.
I don't like the Windows desktop that much (I like the start menu and such, I don't like the look and feel and other things, which is why I'm a KDE fan). But I can deal with it fine; it's the Metro stuff that's really horrible to me.