Thank you for your reply.
One of my calculations is the price of hosting, which differs depending on what type of website it is. So the client first selects the website-type (standart or e-commerce) and then is asked, whether there is an existing hosting.
I gave a value to each of the website types and multiplied that with either the value 1 or 0, given there is no hosting or there is one respectively, which results in the correct costs for the hosting, but there is a “configuration price” issue, which is dependent on the website-type. It is a one time payment, so I thought of just adding this to the total calculation but since it is dependent on the website-type, I don’t know how to do it.