When I put clipon bars on my Monster, I bought relatively cheap reverse retro knockoff mirrors on it, that I bought on ebay.
The quality was okay - they were machined from billet, and the anodizing didn't look like it was going to last (it hasn't, they're going purple), but hey, what do you expect for $60 or so.
So my daughter is blinging out her bike, and she figured she's follow suit, and ordered some Rizome knock-off mirrors from ebay.
The quality of the ones she got was absolutely dreadful. One of the mirrors had two large chips out of the glass, and they are cast and powder coated rather than machined and anodized.
We figured we'd still put them on while she saves some dough for better mirrors, but we couldn't get them to stop spinning as they weren't a good fit on the bar-end. After tightening the clamp screw a little, there was the inevitable "chink" noise as the poor quality brittle casting snapped.
Here's a photo of the offending mirror:

You can see where the mirror has chips in the glass, and also where the powdercoating has chipped.
Also, note where the bracket has snapped. Careful examination of the bracket shows that it's actually cast from cheese, rather than aluminium.

It's not worth the time to try to get our money back for a few tens of dollars. Instead we figured we'd just leave the seller scathing feedback.