I own an HP Photosmart Premium printer 310 series that uses the 564 ink cartridges. When I bought this printer a couple of years ago, I was told that this type of cartridge was much better because I only have to replace 1 cartridge at a time. Well, I am finding that I am buying them all the time. Every time I sit down to print, I find that I need to go out to buy more cartridges. ( most of the time, I buy the combo packs) This is costing me much more in gasoline then what I might have saved when I switched printers and bought the 3 color cartridges. My husband and I have always bought HP products but now I am willing to listen to the other manufacturers. We have a low vision support group that we head up and I have to print labels for mailing. I also make greeting cards and do pictures that I download from my camera. I am finding it is MUCH cheaper to have these things sent out for printing then to do it myself. Very, very disappointed in the HP of today. I hope something can be done to protect consumers like myself from these exorbitant costs. Thank You Jan Rachow