I think it's not very relevant to adjust the price for inflation. You should adjust for opportunity cost instead, like the rate of T-bills.
Yahoo -- I think they were concerned about getting infected by M$'s culture.
At least they'd have a culture then.
At the time they felt very strongly about it. The employees were adamant about the fact that they had a certain way of doing things and they were concerned that Microsoft would disrupt whatever it was they had.
I don't know if it was the right thing for either party, but that's what happened.