I'm sure this is a scam, as the prices are just far too good to be true. If this was a genuine deal, you could make a resonable (by some standards - maybe not Cervelo owner standards!) living buying their bikes, breaking them into components and selling them on eBay.
However, "not an authorized Cervelo dealer" does not necessarily mean "scammer". As an example, Wiggle (one of the UK's biggest and most reputable internet bike retailers) are curretly selling 08 RS framesets at competitive prices. They are not a Cervelo dealer. I've no idea where they are sourcing them from. The 'catch' is that they only offer their own 5 year warranty, but this is clearly stated. As I found, it is possible to match their prices from UK authorised dealers (with full warranty and friendly 'real person' service) if you shop around. Mine came from Primera (highly recommended).