I'm not sure why you would assume that the average school bus buyer can't do a spreadsheet. Our local suburban NY school district is fairly run-of-the mill, and has a budget of $84 million with several million dollars of that being for transportation. We have our own busses and drivers, and they spend about a quarter million dollars a year on diesel fuel.

The Superintendent for business affairs that has an MBA from Columbia and earns $231,000, and should clearly be able to handle a spreadsheet and then making the yearly powerpoint presentations.