From NYT:
The court documents, which are part of a shareholder lawsuit against Yahoo and its directors, were unsealed Monday. The plaintiffs argue that Mr. Yang pushed for the expensive employee retention plan despite reservations from the consulting firm it hired to devise it.
Using estimates prepared at Yahoo’s request, the plan would have cost $462 million to $2.1 billion if Microsoft had acquired Yahoo for $31 a share, the price it initially offered. If Yahoo were acquired for $35 a share, the costs could range from $514 million to nearly $2.4 billion. Yahoo’s management, however, advised the board that the actual cost of the plan would most likely be near the low end of those ranges.
According to the lawsuit, Microsoft had told Yahoo that it was willing to spend $1.5 billion in employee retention.