Re: This is why I've still not bought a personal/home O365 sub.
Some clients of mine with differing use cases of productivity software spring to mind.
Client one, had MS Office 2003 and 2007 in a mixed environment, installed on Windows 7 boxes with a Windows SBS2008 server and used only three products, Outlook, Excel and Word. They upgraded both 2003 and 2007 office installs to MS Office 2013 Home and Business as, at the time we were told a site license was unavailable for fewer than 100 seats. Total cost was just shy of £5k and they'll continue using it for a minimum of 5 years. Projected cost of O365 for the same period assuming no price rises ~ £7500. Saving from not using O365 ~ £2,500
Client two, had MS Office 2003 exclusively, installed on Windows XP boxes with a 2003 SBS server. Their usage included basic spreadsheets and text documents only. They upgraded the SBS to Server Essentials 2012 on their existing hardware, the workstations to Win 7 Pro and switched to LibreOffice and Thunderbird. The workstations they had to upgrade anyway, the server software was £300 or so and the cost to upgrade office was £0.00, projected cost of O365, just shy of £3k over a 5 year period. Saving from not using O365 ~ £3k call it £2.7k if we factor in the SE2012 instead of using OneDrive.
Client three, MS Office 2003 on Windows 7 machines but they're fixated on MS Publisher and have MS Access database requirements. Cost to upgrade to Office Standard and purchase additional Access licenses where required almost £5k, cost for O365 more like £3k. Saving by using O365 ~ £2k
There are savings to be made with O365... if your use case lends itself to it. On the whole, not so much for small businesses.