Thanks. Bought it. I'll post some comments when it arrives.
Pardon me for quoting my own post.
So the $12 Chinese SmartCover knock-off arrived in the mail. It looks very, very close to the Apple one. A casual observer would never spot the difference.
The outer material, at least on the black one I bought, feels like a decent-grade poly, so I'm hoping it'll hold up. The inside is a microfiber but not quite the same grade as on Apple's. Less fuzzy but seems soft enough not to harm the screen.
The 3 hinges in the segments are stiffer than on Apple's original; this is both good and bad - tends to flop/flex less but I've had the magnetic attachment pop off the iPad a few times when attempting to fold it into a triangle.
The other negative is that the spine hinge magnet isn't quite as strong as on Apple's covers, so it's a bit more prone to pop off. Not loose at all, just slightly less strongly bound. It's popped of a couple times folding the lid segments in to a triangle (though note above where I say the segment hinges are stiffer; this may loosen with time) or when putting moderate lateral pressure on to the cover from right to left. With my two Apple brand ones, it's a bit harder to make this happen. But the "fake one" hasn't yet come off while simply carrying the iPad.
The knock-off, at least mine, does not have a counterfeit "Made by Apple..." printing on the microfiber inside cover near the spine. And it came in a simple plastic wrapper and not counterfeit Smart Cover packaging.
All in all, a fairly good buy for $12. The Apple ones are 'better', but cost basically three times as much. I've got an Apple dark gray one and a Product Red one, and now this eBay black one. I really like the way the black one looks on my black iPad mini, so I'll continue to use it for a while.
I'd post pics, but it looks just like an Apple iPad mini Smart Cover, other than the black color... so really not much to see. But if anyone really wants, I will.