Shopper group management on checkout

[fabioweb]

Hello i'm facing a problem that's quite interesting because i haven't find a solution also with other plugins developers..
On checkout page i have radio button field: "Privato" and "Azienda"
"Azienda" is correctly related to the shopper group "Rivenditori" and works correctly during registration steps

Now this is the problem: https://ibb.co/gr0icm

When "Azienda" is selected how can i change product price like in administration settings? https://ibb.co/cJiQq6

As you can see the product for "Rivenditori" is 106€ but this works only if user is logged in..

I need to block the cart page only for registered user?

Thank you