Dot matrix printers are least expensive to purchase, but they are also noisier and slower than other printers. The second type of printer is an ink jet. It sprays tiny dots of ink on to paper. Ink jets can make very high quality images, are quiet, and can also print well in color. The third type, laser printers, use a tiny laser beam to create dots of black powder which are then melted to the paper.
Laser printers are the most expensive, but produce the best quality, and are fast and quiet.
You should consider not only how much a printer costs to buy, but how much it costs to operate. Laser printers are generally cheapest to operate when you do a lot of printing. They are followed by dot matrix and then by ink jet printers, which usually cost the most per page to operate.