Please note that there is more to gaining a patent than just filing an application and waiting. It is possible that this is all you will have to do, but unlikely. Once a patent application is sent in to the Patent and Trademark Office (PTO), it will be assigned to a patent examiner. The examiner will determine whether your invention really is patentable based on the criteria set up by the PTO.

If the examiner does not believe your invention is patentable based on these criteria, he or she will reject it and send you an Office Action. This action explains to you that your invention was rejected and it describes exactly why.

You may receive up to 3 Office Actions before your application will be ... well... to put it bluntly "thrown out". Your patent attorney will likely have a fee schedule set-up for how to charge you for these Office Actions.

Therefore, you will likely be charged a fee for the attorney to write and file your patent application and you will need to pay for its prosecution. Depending on how many Office Actions you receive and the complexity of the prosecution, things can get fairly expensive. Now, it is always possible your invention will be allowed to patent - obviously, the sooner this happens, the less expensive it will be for you.

Here's just a summary of the expenses associated with paying your patent pracitioner (these may of course vary all across the board and there can be additional charges)...

Patent search -- $1,000

Patent application - typically $2,500 up to $6000+ (there is also a filing fee that must be paid to the USPTO)

Fees for prosecution -- $1,000 and up ($10,000+) depending on what happens during prosecution

If your invention is allowed to patent, you will need to pay an issue fee and maintenance fees on your patent to keep it in good standing with the PTO. These fees are at the discretion of the Patent Office so you will have to check on the current costs.