I have known a horse who while at shows nothing bothers them, they behave perfectly and never do anything wrong. When at home they spook at shadows, noises, and other horses. They buck, rear and bolt. If you didn't know better seeing the horse at a show one day, then at home the next you would swear it was a different horse.
Myth= Free/Cheap horses are expensive.
Indy was $150 we keep her in a pasture with a shed for free and she is brushed and fussed over dailey. Other then deworming and feet trimming she isn't costing us anything.