Artists should have a goal in mind and work towards it. It can be hard to find your aspiration without having something to work towards and without understanding what you're trying to achieve.
The cost of being an artist can differ significantly depending on the type of work they produce. Let's say a painting would be more expensive than a drawing.
The materials are expensive, but you'll also need a space to work. For example, if you want to paint in oils, you'll need a studio with ventilation so that toxic fumes can be avoided.