They probably have four or five lawyers on the case - couple partners, two or three associates - all billing on the matter daily. The most junior associate probably spends most of the day billing on it, since he'll be doing all the research and doc review, and even his time is gonna be $250-$300/hr. It'll cost them likely between $50k and $100k per month. It's a lot, but not ruinous for a firm without solvency issues.