A patent gives you the right to stop others from practicing your claimed invention; it doesn’t give you the right to practice the claimed invention. That is entirely counter-intuitive, but that’s the way it works. It is entirely possible for a device or method to be claimed by two different companies or inventors, and neither of them can freely practice the invention.
Usually about $10,000 for a formal opinion. But we have issued opinions for as low as $5,000 and over $20,000. Informal guidance with respect to a single opposing patent can be as little as a few hundred dollars.
No. There is absolutely no requirement to secure a right to practice opinion, or even a right to practice analysis, prior to filing a patent application. Indeed, it is relatively rare for an inventor to do so.
No, but it may well be a good idea to do so. Aside from incurring damages and legal fees, it is very frustrating to spend a year or more developing and getting a product or service on the market, and then have to shut down operations in the face of a competitor’s patent. Depending on market practices, it might also be necessary to buy back infringing product from one’s customers. Note that as a general rule there is no compulsory licensing in the United States. A competitor holding a patent has not obligation whatsoever to license his patent to you.
From search to issuance a U.S. patent typically costs $10,000 – $15,000. Some firms charge upwards of $30,000 to just file a patent, but that doesn’t mean they do a better job. The reason is that such patents very expensive patents tend to focus on length rather than quality. At the other extreme it is terribly difficult to search and write a decent patent for less than about six or seven thousand dollars. Foreign patents typically run about $15,000 to secure, per country.