I think I asked this question a couple of times in the past. Maybe someone answered, I don't remember.. Im becoming a senile bastard. But I always wondered why skin units are more expensive? I always thought they were ventilated by machines which should actually make the costs cheaper? I can't see why the material would be any more expensive.. The only thing I can think of is the demand is less, so maybe its not produced at as much bulk? I have no idea.