OS Worth Upgrading?

I have been running a P2P network with my four office computers simply to share a broadband internet connection. However, I am thinking about utilizing MS Exchange to make it possible to share my database and calander (in MS Outlook)with others. But, this requires me to upgrade from Win 98SE to Win 2000 on the four computers. Is this too much hassle for such a little benefit? Are there additional benefits I would enjoy from this upgrade? Are there any better alternatives? Any feedback on whether this would be worth the money and the effort would be much appreciated.

Why would you have to have win2k on all the computers? I've never used exchange but it seems to me that all you would need to get would be win2k server with 5 users plus exchange. And it sounds like you already have outlook. Can anybody out there with exchange experiance back me up or put me in my place? :)

You do not need W2K or MS Exchange to share calendars/schedules with Outlook. As long as you install Windows Messaging on each machine everything will work fine. Windows messaging is included on the Windows98 installation CD's. Just browse the CD--you'll find it. I don't remember the exact folder name....