Okay, as for what is cheaper to keep, go with the Canon. The cartridges have a larger volume of ink (about double what the HP has) for only $4 more per color, and is cheaper on the black.

Now if you are doing more graphical work, I would actually recommend the Canon Pixma iP6700. The 4300 is okay, but the 6700 gives you the two photo or light colors, and get's rid of the text (pigment) black.