User-generated news site Digg has been working with influential investment bank Allen & Co. (the ones that recently got Slide a half billion dollar valuation) for a few months now, and pitching big tech and media companies on a sale. And despite a number of false starts, this time a sale looks like it might actually happen, and soon.Four companies are in heavy due diligence with Digg - two media/news companies, and two big Internet companies - Google and Microsoft. And Google and Microsoft are on the verge of making their bids.Digg is prepared to take less than the $300 million Allen & Co. were floating late last year. Google, our source says, will likely bid $200-$225 million, which Digg would likely accept.Microsoft is looking at a somewhat lower price. That makes sense, since most of Digg’s revenue today comes from a three year advertising deal that Digg signed with Microsoft last year. That deal has revenue guarantees - and Microsoft may be hesitant to value Digg based on revenue that they supply.Read here the full story from TechCrunch on Google, Microsoft Said To Be Preparing Bids For Digg