The cost varies slightly with each person.  The FAA requires that a person must have a minimum of 40 flight hours before being eligible to take the test to obtain your license.  Many people average around 55-65 flight hours when they take their test.  Cost will also be affected by which type of aircraft you fly.  Many people train in a Cessna 150, but taller people like myself unfortunately find it much more comfortable and sometimes even a necessity to train in a Cessna 172 or some type of Piper 4 seat aircraft.  Being able to fly more than once a week is a huge money saver because it lessens the amount of time needed to review what you learned last lesson and allows you to more quickly build on what you learned in the previous lesson.  There is quite a bit of reading and studying when you go to get your Private Pilot License.  The better you are at keeping up with reading, studying, asking me questions from your reading, studying some more, and than studying after that will dramatically reduce how much it costs you to get your license.  A reasonable estimate ranges from $4,500 to $6,500.