You have to produce a working model and apply for a US patent. I suggest you contact a patent/trademark attorney listed in avvo or confer with the county bar association. If you own the patent you can license manufacturing rights out to others for a fee. If the US patent office determines that the product is not a unique invention, you have to pay license fee to the person or company which holds the patent. You can get more information from www.uspto.gov/You might find my legal guide on selecting and hiring a lawyer helpful.
You might find my legal guide on Is it Legal? Is it Illegal? helpful.
You might find my legal guide on the understanding the different court systems helpful.
You might find my legal guide on legal terms used in litigation helpful.
(Even if you are not filing a lawsuit this information can be useful).
You might find my legal guide on commercial litigation helpful.
Mr. Sarno is licensed to practice law in NJ and NY. His response here is not legal advice and does not create an attorney/ client relationship. The response is in the form of legal education and is intended to provide general information about the matter in question. Many times the questioner may leave out details which would make the reply unsuitable. Mr. Sarno strongly advises the questioner to confer with a local attorney about this issue
Disclaimer: This answer does not constitute legal advice, does not form an attorney-client relationship, and should not be relied upon to take or refrain from taking any action.
First, although it is helpful to have a working model or prototype, it is not a requirement for patentability.
Second, you want to be sure that no one else has invented your invention before. You may review my AVVO guide at http://www.avvo.com/legal-guides/ugc/how-to-search-for-patentability. For patentability you should be reviewing both patent references and non-patent references. You should be aware, however, that there is a significant difference between patentability and infringement. I have a handout at my website that you may want to review on this issue. (http://www.oregonpatent.com/pat&infringe)
Third, you need to be concerned about dates. If you have kept your invention a secret, have not used it in public, and have not offered it for sale, you are in the best position. If you have done any of these things, you may have started a one-year time period that, at the end of which, you will not be able to get a patent. This is very tricky and you will want to speak with a lawyer about it if there is any question.
Fourth, you need to decide if you want to file a provisional or nonprovisional application (which can be a utility or a design patent application). A provisional application can be thought of as a place holder application that, after one year, disappears unless you file a nonprovisional application claiming priority to the provisional application.
Fifth, if you plan to file a provisional, although I specifically don’t advise it, you may be able to “do it yourself.” This is only true if you have kept your invention a secret. If you have disclosed your patent (including offering it for sale or using it in public), I highly advise speaking to a patent attorney. I have information (including fees) about provisional patents at http://www.oregonpatent.com/provisional.
Sixth, if you plan to file a nonprovisional patent application I highly advise speaking to a patent attorney. There are many nuances to the patent system that are almost impossible to learn from a book, software program, or other source. That being said, you may want to check out the U.S. Patent and Trademark Office website at http://www.uspto.gov/web/patents/howtopat.htm.
Seventh, once a nonprovisional patent application has been filed, you are in a waiting period. I have a timeline available at http://www.oregonpatent.com/process that includes estimated times and fees for each stage of this process.
You specifically asked about costs. Some of the handouts listed above provide a guideline on costs. You also can check out new patent application fee calculator (http://www.oregonpatent.com/calculator) that can be used to calculate an estimate range including most fees for the FILING of the patent application (but not subsequent fees). Please note that the estimates provided by the calculator must be confirmed before they may be relied upon.
The only inventions that you'll will need a prototype to patent are those that no one will believe you actually invented like a perpetual motion machine or a time machine. If you have something like that, and it really works, I'll prosecute for cost.