Please explain this KO Reissue to me

During my off years from Transformer collecting I completely missed many of the reissues, with the exception of the Takara book releases. However, there's one G1 figure left that has eluded me (see the grail thread) and that's Mirage. I have all of his other incarnations save for G1, and I never even had him as a kid.
However, in trying to snag one on eBay I keep coming across these auctions featuring KO Reissues or KO Remakes. What exactly are these? They say unofficial release so are these just very well done knockoffs? If so why are they so damn expensive? Mirage seems to be one of those figures that won't see an Encore or reissue due to whatver reasons (trademark, lost molds, etc) so it seems like this may be an expensive aquisition.
Any advice or insight into these KO toys is appreciated!
However, in trying to snag one on eBay I keep coming across these auctions featuring KO Reissues or KO Remakes. What exactly are these? They say unofficial release so are these just very well done knockoffs? If so why are they so damn expensive? Mirage seems to be one of those figures that won't see an Encore or reissue due to whatver reasons (trademark, lost molds, etc) so it seems like this may be an expensive aquisition.
Any advice or insight into these KO toys is appreciated!