Not all steam cookers are the same. There is no general answer to this question, as there is a wide range of options to choose from. The price range for steam cookers is between €10 and €300.
Criteria that influence the price include the space required, the material and the energy supply. So before you buy a steamer, you should be clear about exactly what you want.
Steam cookers start at a price of 10€. This means that they are available for very little money. However, quality has its price here too.
High-quality steamer pots start at around €40 and can cost up to €300.