Also, they take up space in super markets, if they wanna sell them there. If they just wanna sell them on a webshop, they still have to package and send the parts which costs a lot of money aswell. I think this is the absolute best case, and I (might be biased because I own a 3d printer myself) think 95% of people knows someone who have a 3d printer, that would love to print something like this for other people