Costs and savings of a videoconferencing system

I have been hired as a telecommunications consultant to help an organiztion assess the benefits and potential cost savings associated with installing videoconferencing systems at each of the firms's six locations. I have determined that the cost to establish each video conference facitlity is $60,000 and that each facility will have an annual operating and support cost of $20,000. In the first year, I estimate that videoconferencing will save the entire firm approximately $400,000 in travel expenses. The savings are expected to increase at a rate of 5% per year.

I need assistance in developing a spreadsheet to analyze the costs and savings over a three year period.