AMA is worth it because of the liability insurance you get with it. If you fly your plane and you hit somebody, their house, or their car you could find yourself in a lawsuit that could cost 6 or 7 figures. Since you're a minor your parents would be held liable in a situation like that. With the AMA you are covered with insurance. For that reason alone it's worth every penny.

As far as the drive. Contact the club, you might be suprised at how much they may be willing to help. Who knows, there may be somebody close to you that you could ride with. A lot of pilots are really willing to help out kids your age. A few years ago I had a 14 year old that I picked up and gave a ride to the field when he was coming out flying. He offered to chip in for gas, but I wouldn't take it. So instead he would bring the sodas for us to drink at the field. But you never know until you ask.

Just some food for thought

Ken