Only 2 options ?? Ink et vs Laser ?
Do consider their speeds if your users need it....20PPM vs 36 PPM (per color image)
Then look at the toner vs ink per cartridge page-yield vs cost as well and go a cost comparison as per 100,000 mono & 100,000 color (depending what color images you print)
Next is to look at other parts like ink print head costs (inket) and fuser costs (laser) as this can also be a killer for some brands.
Also look at add-ons like the 250 or 550 sheet paper tray etc.
Lastly is to see the monthly duty cycle to see if the machine can handle your loads