You answered your own question: they want to have the opportunity to maximise earnings per customer by attempting to find the maximum each and every customer is

You answered your own question: they want to have the opportunity to maximise earnings per customer by attempting to find the maximum each and every customer is willing to pay. This can only work when the pricing structure is opaque. It is one of the reasons why I shun products and services which require me to contact the vendor to find out what they expect their customers to pay.