Microsoft’s Office 365 for enterprises ranges from $2 per user per month for basic email to $27 per user per month for Microsoft Office Professional Plus desktop software that includes email, voicemail, social networking, Web portals, voice, video and Web conferencing, 24-7 phone support, on premise licenses.
The Office 365 package for small and medium-sized businesses includes Office Web Apps, Exchange Online, SharePoint Online, Lync Online and an external website for $6 per user per month, along with a 99.9% uptime guarantee. There is no phone support. These customers have to rely on the website. In all, that's $150 per month for 25 users.
Google Apps Premium Edition includes Gmail, Google Calendar and Docs, Google Talk, Google Video and Google Sites with an additional 18 GB of Gmail storage with a 99.9% uptime service-level agreement. It costs $50 per user per year. For support, these users can use Google’s help website, a user forum or a 24/7 technical support phone line.