how to configurate defaut user that can only see price when he is reistred

[TAIWAR]

VM 3018
hello I want to know how to configurate defaut user that can only see price when he is registred,
in fact anonyme user can see the product but not the price , I want defaut page for all product use "ask a price"
The customer must be registred to see the price of the product

Thank you.