Depending upon the aircraft that you wish to fly, the cost of obtaining a pilot's license can vary from $5,000 to over $250,000. To be a commercial jet pilot, flying 777's, Airbus A380's, and other big, luxury airliners would take a lot of simulation time, classroom work and observation time in a cockpit behind instructor pilots. You have to pay for the simulation time, the time for all of the workers involved with running the simulators, maintenance on the aircraft that you train on, fuel, flight plan filing fees, airport fees, runway fees, aircraft controller fees. All of that paying for people and materials, and on top of the class instructor, there are flight training school fees, uniform costs, and those really cool sunglasses!
If you want to fly a small, 2 to six seat Cessna single or twin propeller airplanes, then the costs come a bit more close to earth. You can, assuming that you pass all of your tests on the first run, obtain your license to fly a Cessna 120 type plane for under $25,000. It ain't cheap! But, as you can see, the smaller the plane, the smaller the financial burden. And, you can start off with the least expensive license, get hundreds of hours in the air (control and flight plan training, night flying and all with no problems) in a smaller plane, then work your way on up the growth chart of airplanes, until you get to the plane that makes you drool the most. Want to fly a supersonic jet? You may have only one option, and that option carries no guarantees that you will become a pilot, only that you will be in the Air Force, at a time of war.
You can join the Air Force to become a pilot, foregoing the monetary input needed to retain a pilot's license going through a pilot training facility. However, when you join the Air Force, you are in no way guaranteed to even see the inside of a cockpit during your entire military career. They can put you in kitchen duty, aircraft maintenance, front-line infantry, wherever they need you and your specific skill set the most (read; healthy and strong, you are going to see the war, but from the ground). Going the Air Force route, during a time of war, there is a fairly good chance that you will be coming home in a pine box.
However, assuming that you successfully complete all Air Force basic training, make the roster for aircraft training, and pass the muster in flight school, becoming a pilot for the Air Force, you will be able to fly any plane on the market once you have successfully completed all military obligations. However, the scary part of this is the completing all of the military obligations, This could include a lot of flying in Iraq, Afghanistan, Sudan, the Arctic, and, gads, even Hawaii!
And, yes, the Air Force pilots get really cool sunglasses too! And, once you have left the Air Force, with honours, you can get a career flying jumbo jets for passenger carriers, search and rescue, bush pilot work, or anything that you desire. With the chances taken with your life going the Air Force route, it should be the last option for you. If you figure your personal finances would not allow you to obtain the loans necessary to pay for flight school, it may also be your only option. Or, you can take a mini-course, where you can only fly with a qualified pilot beside you at all times during flight and pre-flight procedures.
Fly on you crazy diamond.