-how many pages you print- inkjets are cheaper if you don't do as much
-if you need colour- lasers are more expensive in general, but a B&W laser is less eye-watering than a colour one
-if you need lightfastness ( if you do, you'd need a pigment-type inkjet, expensive, and so are the inks, cheaper inkjets and inkjet inks are not
lightfast; lasers, I don't know about lightfastness)
-waterproof- if you need this, laser, if you don't need it often, you can get spray-on waterproofing for injet-printed pages. Or for things that don't need to fold/bend, like posters, use a laminator.
-special and/or textured papers; you need an inkjet, lasers use paper only
-speed; if you are doing lots of copies of a document- lasers are far and away faster.
I have a large (A3+) pigment printer for work (inkjet) costs me well over £100 for a set of manufacturer's ink.
