Foreign people speak in foreign languages.
As a case study of the extremely high cost of foreign patents, consider Jim — the engineering manager of a company which filed a U.S. patent application this year at a cost of, let's say, $15,000. Ten months later, Jim receives a letter from the company's attorneys advising him of the deadline to file one or more corresponding foreign patents. Jim is patent savvy enough to know there is no such thing as a “world-wide” patent. Based on input from Jim's team, he decides to seek foreign patent protection in Japan, Germany, the UK, France, and China since that is what his company did with its last patent application. In a month or so, Jim receives a bill for $4,000.00 for something called a “PCT patent application.” Not too bad, he thinks.
But then Jim receives a bill for almost $5,000.00 for something called a “Demand” and filing a reply to something called a “Written Opinion.” He is unsure what those things are and, worse, he later receives a bill for $8,000.00 to file something called a “European Community Patent,” $7,500.00 for filing a patent application in Japan, and $4,500.00 for filing a patent application in China.