I buy my ink cartridges online in bulk (usually 5-6 cartridges at a time). I find it to be cheaper when I find the right deal online than getting them at the store. I also don’t buy the name brand cartridges – instead I buy “compatible” inks. Which is just another way of saying the generic brand.
123inkjets is a site I order from often. Right now they are offering 15% off all their “compatible” inks plus FREE shipping on ALL orders (contiguous US states only). Shop now and use promo code FLAG by 5/29/12 at 9am PST.