I need to buy some toner for a HP Laser Jet 8550N, and I have discovered that you can't just buy "black" toner or "cyan" toner, instead the refill bottles are branded to specific printers, and the prices seem to vary wildly, seemingly without any distinguishable pattern.
So my question is, what makes toner A different from toner B? Can getting the wrong type damage my printer (or cartridge) in some way? Can I find toner for other printer models that would be cheaper and equivalent?