Patent-related legal services, including litigation, bulk large for many law departments, and data appears frequently about these services. The Wall St. J., June 9, 2007 at A7, offers a number of insights.
“It is cheaper to obtain a patent, which can cost $5,000-$25,000, than to invalidate one. Legal fees average $4.5 million in disputes where more than $25 million is at risk” (See my posts of May 13, 2007 on Microsoft’s spending; and June 11, 2007 on the costs of patent litigation in the US.). I do not know whether this average includes the legal costs of all parties to the lawsuit.
The number of patent lawsuits filed in U.S. courts has risen since the 1990s from about 800 per year steadily up to around 2,700 per year. For the past three years, that total has stayed fairly constant (See my post of Aug. 5, 2005 about the choice between a generalist litigator or a patent lawyer to handle a case.).