You can recycle a lot of the equipment from your trainer to your next plane.
Weedeater engines can be had for practically nothing and if you are able, they can be converted to RC fairly cheaply.
Planes this heavy will do great damage to themselves upon impact for sure..but in a scenario where an experienced hand is in charge of the training sessions a "Weedeater Scale" trainer that was built from scrap lumber and Tyvek covering would be a very cool [and feasable] way for some guys to learn how to fly.
Definitely not for the "mainstream" ....