There's good reasons to want to own a simple monochrome black and white laser printer for your Mac laptop or desktop: Dirt cheap cost per page at high speeds for your basic printing needs. Paired with a color inkjet all in one, you can have the best of both worlds.
For a dirt cheap monochrome Mac OSX compatible laser well under a $100 - ponder Brother's 2240 USB laser. Over the years, this bargain printer has moved up from 300 to 600dpi, improved print speeds, and now offers 2-sided 'D' duplex printing options.
For a bit more: The next step up in Brother's highly affordable Apple friendly laser line-up. In addition to the the convenience of Duplex, 2-sided printing, 2270DW also offers Airport wireless or Ethernet connectivity (as well as USB2) for your Mac network printing needs