Thank YOU Microsoft! New Price Increases!

Licensing client access to the latest versions of many server products—including Exchange and SharePoint Server 2013—will cost more under certain conditions starting Dec. 1, 2012, although some volume license agreements insulate customers from price changes for several years. Customers generally have the option to license client access to on-premises server products by purchasing per-user or per-device licenses. The two types currently cost the same, but per-user prices will increase 15%, while per-device license prices remain unchanged. Regardless, per-user licensing will generally remain more cost effective in organizations where employees use multiple devices in the course of business.

More information here