Unfortunately, there is nothing cheap about patent applications.
I haven't obtained one (yet), however I decided back in 1996 to forgo going through an attorney to do the search. They were shining me on about an initial "consultation" in which they would perform a "preliminary" patent search for me, all for the low, low price of $800. What they probably would have done is a more extensive search, coming up with what is known as prior art, and then kept stringing me along as they revealed more information, for more money of course.
Instead, I took that $800, flew out to D.C. and spent a couple of days at the PTO office in Crystal City, taught myself how to do an old fashioned patent search, and came up with reams of data for not just one idea I had, but three.
And I also was able to tour the Smithsonian on an off day.
It's a little easier to do patent searches yourself now, with the internet, but I would suggest you get your hands dirty doing it the old fashioned way, either at one of the 23 PTO depositories spread throughout the country or at the PTO itself.
In the end, though, you'll probably have to go through a patent attorney to help you write the actual patent. It's complicated, and time consuming. You really have to cover a lot of bases in order to protect all the features that may be inherent in your design.
Speaking of which, what type of patent are your going for? There are 3 types, Utility, design, and plants. There are a couple of good books out there, one in particular that I'll give you title when I have some time.
