Microsoft has one of the world's greatest health insurance packages. They also have one of the best overall benefits package (much better than Google, for example). They are saving multiple years' worth of salary per employee by letting them go. And the layoffs have allowed them to cancel/delay the purchase of several lots of real estate. I actually thought it would be more than 1.5 billion estimated.

Also, they are apparently laying off a lot of LCA (lawyers) who probably are very well-paid.