James works in the Solutions Partners team in Microsoft UK, currently specialising in training and readiness for partners selling and supporting Small Business Server has an article on IT Management decision for Small Business. The will help you save a lot of money e.g. leveraging Windows Mobile, whilst maximising your investment e.g. Active Directory and Group Policy.
Why companies move to a server environment?
Usually, the business reasons for upgrading to a client/server architecture are:
• Centralised storage of files in an organised way
• Business-quality email (using Exchange) in which email is retrieved centrally and then distributed to each “client” workstation
Technically the security, maintenance and management functions of a server also represent a great improvement over peer-to-peer networks.
All of this can be managed easily without complicated manual intervention. You don’t mention in your question whether you have an IT partner for your business, but your need for support should heavily reduced with a server and the expense should be similarly reduced too. Problems can be solved remotely, and, in any case, a policy-driven IT architecture reduces the incidence of problems in the first place.
Our point here is that, whilst Exchange, Blackberry Server and lots of other software goodies are your reasons for becoming server-based, the financial benefits to your business also stem from technical efficiencies.