Laser printers are by far the most cost effective printers when doing large amounts of black and white prints.- no comparison. Toner cartridges cost much more per cartridge, but do hundreds if not thousands more than a typical ink jet, not to mention that ink jets are not as clear when it comes to quality. I don't know for sure about color lasers, but I would assume the same.
Actually for anyone that does any decent amount of printing it is cost effective in the long run for lasers, but there is more up front cost. But for the average printer a laser cartridge can last years unlike the $30-50 ink jet cartridge that can last months.
Do a google search for laser vs ink jet printer cost and I bet you come up with many web sites that examine the cost of both. Mac world often does a comparison of cost per print and I know for sure the per print cost is cheaper for laser every time.
Laser printers tend to be better quailty products as well as long as you get a decent one.
It is better recently, but from what I remember about color lasers, the color accuracy is not always great, depending on how accurate you need the prints to be. If you designate a certain PMS color you might end up with something quite different with a normal color laser, unless you get a very expensive one.
Unless things have changed drastically in the last 5 years, I would go with a black and white laser and outsourse the color stuff, but that is just my opinion and based on my graphic design/printer background from about 5+ years ago before I became a teacher.
Good luck