The Yahoo that was sold recently did not include the Alibaba stake. This is where the key value of Yahoo lies.
If you break it down, the Yahoo Alibaba + Yahoo Japan stake + Yahoo's final selling price equals Microsoft's $45/share offer
It's sad Yahoo chose to throw in the towel and spin itself off as an internet company rather than use the Alibaba stake to resuscitate.
Source: I was at Yahoo back then.
A business is a business, and if you lose it makes sense to admit it.
Actually, if mayer didn't sell a huge chunk of alibaba stake, the BABA stake by itself would be worth 120% of microsoft's bid.
YHOO owned 25% of alibaba. Alibaba is worth $400 B today. Microsoft's offer was $45 billion for YHOO.