Out of a total of +/-30 lights I only have one that's still completely stock, and that's a 3x XML 3C SRK from fancyflashlights/CNQG. I got it very very lightly used from another member - before handling/using it there's no way I would have paid full price for one, but now that I know the difference from the implausibly cheap ones, I would, if I needed another one. I haven't even been tempted to disassemble the head or peek at the driver. I know what's in it, and I don't think there's anything I could do to make it better...
Sometimes cheaper is just cheaper, but sometimes it means you get something that's been nickled-and-dimed to death to the point it's not even usable anymore. Sometimes spending more is worth it, with these SRKs I have seen/had too many bad ones to try to skimp on them anymore.