The costs can add up quickly no doubt, and there will be post-filing costs once the Patent Examiner starts to examine the application filed, but those will be the subject of a future article. Still, you should budget at least another $5,000 to $7,500 for prosecution and issue fees to the Patent Office.y way of example, you could probably find an attorney to write a patent for a business method or computer software for quite cheap, but a cheap computer related patent would not be nearly as strong as a patent application costing $20,000 or more. The devil is always in the details.