Yes, they save ink, but always at the expense of picture quality.
Sorry, there's no free lunch when it comes to laying down the ink. Of
course most printers have several printing modes available, including
a "draft" mode that reduces ink consumption--but you wouldn't expect
to use this mode for best printing quality. Buy a half-gallon ink kit
and a handful of hypodermic syringes and you'll be printing until
WWIII for under $100.