Light printing for school and home correspondence can easily be handled by a low cost ink-jet. High volume printing including things like community bulletins, church newsletters, etc. is best handled on laser printers. This is one of the trade-offs that you will have to make in printer selection. Ink-jets can be purchased for low cost, but the supplies can quickly eat up any savings. Laser printers are more expensive and their toner cartridges cost more than a set of ink-jet cartridges but they will produce many more pages.
Laser printers deliver the lowest cost per printed page of any output device.
Producing one set of 30 color overhead transparencies can consume the ink. Costs of operation vary widely and depend on what type of printing you do. Standard text is least expensive. High density graphics in color is most expensive. Paper costs need to also be considered.