I don't think so. I would think the technique of dividing CPC by the prospective conversion rate might be useful in determining ballpark costs for Adwords as one specific channel of marketing, but it's quite a leap in logic to say "this is what your product's price needs to be".
The idea that a potential market can be understood through such a swift and simplistic means is taking the paradigm of Adwords testing to absurd lengths.
I think the OP meant that this is the bottom line margin you need.
As an Auction Marketplace, with highly motivated prospects, searching for what you offer, only a click and a buck away, and an extremely low barrier of entry, I would argue that Adwords is as close to an efficient marketplace as possible, and represents the high end of the cost per customer within the framework of profitability.
The idea that a potential market can be understood through such a swift and simplistic means is taking the paradigm of Adwords testing to absurd lengths.