One of the most important is the Cost of Ownership over the life
of the printer. Watch out for the cost of colour inkjet printer ink cartridges.
A serious disadvantage of many colour printers is that when a
single colour within the cartridge runs low, you have to replace
the entire colour cartridge (despite the other colours being
perfectly OK). With six or more colours to a cartridge, this
problem becomes even more significant. Many printers now offer
separate cartridges for each colour, so you can replace individual
colours as and when necessary. This can result in a reasonable
saving in ink costs.