We have three printers which we use.
In my office, I use a Canon multifunction device. It has a B&W laser printer, a scanner and can act as a copier and a fax machine. Does pretty much everything I want and was very reasonably priced.
I also occasionally use a very old 9-pin dot matrix printer when I want to print off very low quality prints on thin paper. The cartridges for it are a little hard to find, but I can order new ink cartridges almost literally a dime a dozen.
My wife is much more demanding. She owns an HP colour laser printer and an HP Inkjet printer. She uses the Inkjet for very high photo-quality prints and uses the Colour laser for everything else, including draft prints.
Here's been my own personal experience...
If you absolutely want the lowest cost per page and I mean the LOWEST cost per page, Dot Matrix printing is the only way to go. However, it's also slow (In comparison to everything else on the market), very noisy, the print quality is crap (Unless you go 24-pin dot matrix, then it's not too bad) but it is REALLY cool to watch...
Barring Dot Matrix, Laser Printers have the lowest cost per page out of all of the printers out there. It doesn't matter if you are printing a little bit or a lot, they still have the lowest cost per page. The only disadvantage laser printers have these days is that they still have a warm up time.
Laser printers have one massive advantage over Inkjet printers, they don't clog up if you don't print for a while. They don't run massive ink-wasting cleaning cycles every few pages and the best part, the toner cartridges, while expensive, usually last around 5,000 pages as opposed to Inkjet cartridges which last 1/10th of that.
For the least amount of fuss and trouble, laser printing is the only way to go.
However, if you like printing photos, then Inkjet still provides a much better amount of quality over Laser printers.
But I'll give you a hint... professionals only use Inkjet printers for two things, large scale plotters and extremely high DPI photo printouts. Laser printers are used for pretty much everything else.