Fast draft or everyday modes will save you a lot of ink.
The most savings has come to me in refilling my ink cartridges myself. I buy my ink from www.encoreink.com (a homeschool family). The ink is not "universal" refill ink, but is the ink for your make and model printer.
A brand new black cartridge for my printer costs $28. I bought 8 oz of black ink from Encore Ink, along with the supplies needed to refill, for less than $25, and it will refill my cartridge something like 8 or 10 times.
Encore Ink has great, speedy service, and wonderful support.
HTH,
ChrisN