One of our finest legal minds and professor here in the UK reminded me ::
"that only 1% of patents produce any real income - 10% break even on costs of gaining protection and the rest lose money. Getting a patent is perhaps the easiest part of the process."
Founder of the GNU project and director of the Free Software Foundation movement, Richard Stallman once quoted an Economist as saying "you can compare the patent system to a time consuming lottery". Richard Stallman's experience is that only the smartest, most committed survive and even then there are a billion booby traps along the way.
In short, it is only worth entering the process of applying for a patent if :
A. Your idea is likely to be currently 'entirely unobvious' to the world community at large
B. Your idea can be leveraged significantly once you have obtained a patent
C. You are prepared for a long, but victorious intellectual battle
Even then there are dangers along the way - but as with many successful entrepreneurs - Bill Gates, Steve Jobs, Woz, Ray Ozzie etc, you can get very, very rich if you play the patent game well!