There are two ways to buy Office 365. You can buy at the retail price from Microsoft using Microsoft Services Online. Under MSOL you will pay Microsoft directly. This is the required choice for non-commercial accounts and an optional choice for all other accounts.
If you are purchasing Office 365 for your organization SDS offers significant discounts not available through MSOL. Please contact SDS directly to get a free no obligation quote: firstname.lastname@example.org.