The topic of costs is definitely a consideration. Another good reason is to get the patent and try to sell the patent. A patent also looks good on a resume, and if spending a couple thousand dollars to get a patent helps land a person a job they couldn't have otherwise have obtained that pays well, then I'd say this is a valid reason to seek a patent.
Patents are evidence of a creative mind, and companies like creative minds.
Below is a typical breakdown of costs associated with obtaining a patent in the United States through us as of October 2000. This varies on the complexity of the invention, as the amount of time required to prepare the application determines the cost. A new printing press takes more time to write up than a new fusebox. Some simple inventions can be done for about 1500-1700. Make sure you get a commitment on price from who you hire.