A good third plane is the Global 25 size Me-109. I had my brother solo on it before he moved onto others.

The reasons:

1. The plane is cheap.
2. It looks good and is semi-scale.
3. If you get to where you can fly it well without any problems, you will be able to fly just about anything out there.
4. No matter which direction you go, it is a good step and may save you money down the road.
5. It is a fun little plane that is very aerobatic.
6. Fits in the car with the wing on it.