My experience over 23 + years of flying instructing is the total cost of your license is almost totally controlled by two factors.
1) How often you fly. More is better as if there is a delay between flights you end up spending money relearning things you have already been taught but have forgotten or where the skill has faded. Starting in the summer is better in the winter as you get fewer cancellations due to bad weather and 3 lessons a week seems to be a good balance between maintaining recency but not being overwhelmed with new information and experiences.
2) How hard you work. Most of the knowledge piece of flying is in books. You can study it your self or pay big bucks to your instructor for him to teach it to you. I tell all of my students to keep a diary of their training. Make an entry after every flight with what you did, where you were told you need to work on and a list of questions on anything you did not understand for the next lesson. When it is raining and your lesson is cancelled sit in the aircraft and go through all you checks and emergency procedures.
Finally I tell everyone to budget for 50 % more than the school quotes for a 45 hr PPL. As was stated in earlier posts almost nobody does the course in the minimum time and you do not want to run out of money with the course 80% done.