Can I buy Microsoft Entra and if so, how much does it cost?
No, just like Purview for Compliance there’s no single SKU to purchase for Entra. Rather, if you have Azure AD basic today, you can use the Entra portal to manage users, groups etc. just like you use the Azure AD portal today. Further, if you have Azure AD Premium P1 or P2 licensing, these features will be available in the Entra portal just like they are in the AAD portal today.
However, Entra Permissions Management is a separate product, that you license on a per resource basis. You can still use the Entra portal for Azure AD and Verified ID tasks, even if you don’t have licensing for Entra Permissions Management.