There are a few compelling arguments in favor of Office 365. Let’s take a look at three reasons Office 365 might be the right choice:

Microsoft hasn’t yet shared what the price tag will be for the new Office 2013. But, unless it follows the same bold path laid out in offering Windows 8 for a mere $40, history suggests the new productivity suite will start somewhere in the $150 neighborhood.

Office 365 plans start at $4 per month. Small businesses can get access to Exchange, SharePoint, and Lync in addition to the core Office productivity applications for only $6 per month. Larger businesses that want to take advantage of Active Directory integration can do so for $8 per user per month.

Breaking those down, it takes more than three years to reach $150 based on the $4 per month plan, and more than 18 months under the $8 per month plan. 

Of course, those are the current subscription prices and plans for Office 365, so those figures are subject to change as well.

What else do you get with your Office 365 subscription? An IT department. Sure, you can set up your own Exchange Server, SharePoint Server, and Lync infrastructure. You can manage and maintain the desktop Microsoft Office software, and install the patches and updates every month yourself. How much will that cost?

Consider that implementing the same capabilities in-house requires servers, and network infrastructure, and IT personnel to install, manage, update, and maintain it all. Plus, you still have to buy and maintain the Office software itself.

With Office 365, Microsoft takes care of all the dirty work so you don’t have to. Updates, patches, and upgrades just happen in the backgroun​d without you needing to worry about it. When the server crashes, its Microsoft’s problem. When a hard drive needs to be replaced, Microsoft will handle it. You get the benefits of using Office without any of the headaches of updating and maintaining it all.

Office 365 lives in the cloud. That means you have access to Word, Excel, Outlook, and other Microsoft Office tools from anywhere you can get a Web connection, and from virtually any device--Windows or Mac desktops and laptops, Android devices, iPhones, iPads, and other smartphones and tablets.

This isn’t quite the selling point it once was for a couple reasons. First, even with the desktop Office 2013 suite Microsoft is pushing users to save files to the cloud-based SkyDrive, or to a SharePoint server by default. So, there’s no reason the data can’t be accessible regardless of whether you choose Office 2013 or Office 365.

The second reason it may not be all that compelling is that Office Web Apps are already available for free from the SkyDrive site. So, even without Office 365 users can create, view, and edit Word, Excel, PowerPoint, and OneNote files from the Web.

For businesses, though, SharePoint, Active Directory, and other elements of Office 365 that go beyond simply creating and editing Office documents still make Office 365 a better value.

Your mileage will vary of course. There are a number of factors involved in calculating the cost of purchasing, installing, configuring, updating, and maintaining Microsoft Office and the accompanying back-end services versus the ongoing subscription costs associated with Office 365. Office 365 is a solid service providing tremendous bang for the buck, though, so it won’t be easy to beat the value it brings to the table.