I know people have talked about these in the past, so I thought I'd share this...
They say they're a authorized seller. I bought one, it looks to be legit. I'm tossing the mkv rings and putting on a new Spiderring I had laying in the parts bin.
Not a bad deal though, I think Cannondale Experts lists this at $975
Cannondale Hollowgram Sisl Crankset 172 5mm Standard with MKV Rings and Spider | eBay