< sketch of your toy concept 3 >
Design 2:
Flat surface with a glass screen on top to prevent the metal shavings from coming out. There is a magnetic pen and various magnets with different patterns. Kids can make designs and patterns on the drawing surface while not making a mess since the metal shavings are sealed inside.
Age range for toy would probably be around 3-8.
Should be fairly easy to manufacture. so probably 15$>