That would make a Groupon acquisition the largest ever for Google, if completed. The "if completed" phrase is important, as the sources, close Sources said a deal for the deal-of-the day site isn't complete, though it might be completed as early as today. It is, of course, possible it still might fall apart.
In addition to Boomtown, the New York Times is also reporting a similar amount for the deal.
This also jives with Boomtown's original story. There they noted any price would be well above the $2 billion to $3 billion reportedly offered by Yahoo! $2.5 billion didn't qualify, but $6 billion in total certainly does.
Earlier this year, Yahoo! made an offer of $2 to $3 billion for Groupon, but was rejected. Reportedly, Google then offered Groupon $3 billion to $4 billion. Also, rebuffed, Google has come back with a bigger wallet.
As we've said before, Groupon would be great if (when) integrated into Google Places. It seems a natural fit. Google has been trying to enter the local advertising space, but has had mixed results.
It will be interesting to see what regulators have to say about any acquisition, assuming it reaches fruition.