Kennelmaster, TruBlu02 is right on the $. Another thing to consider is speed and reaction time. Most trainers fly around 45 ot 60 mph. A good mental exercise is to calculate 60mph into feet per second, even at 300 foot altitude max correction time is 2 to 4 seconds for an RC plane going 60 mph. If you "get behind the plane" (mentally) it usually is all over.