Thank you for your post. Skype for Business pricing is included in Microsoft Office 365. Skype offers three business packages: Business Essentials, Business, and Business Premium.
The Business Essentials package is $6 per month per user and only includes web and mobile versions of Office Applications along with Exchange, OneDrive, SharePoint, and Microsoft Teams
The Business package is $10 per month per user and includes Outlook, Word, Excel, PowerPoint, OneDrive, and Access (PC only).
The Business Premium package is $15 per month per user and includes everything in the Business package plus Exchange, SharePoint, and Microsoft Teams. For more information, click here