Thats why I have a couple little 46 size glow planes for practicing 3D. Most of the time the engine and electronics will survive a crash. Another $150 for a new airframe and your flying again in a week. Maybe $300--$400 in a little airplane. Crash it--buy a new airplane and put all your gear in it. Go do it again.

Get smooth on a little 46 size plane and then grab your big plane and start doing it up about 100'. It's a lot easier to do it with a bigger plane, so if you can get a little 46 plane to do it--you'll be lookin' like a pro when you grab the gasser.