For one of the smaller cheaper photo printers, such as the iP5200 or iP4200, roughly how many 6*4 colour photograps do you get from the cartriges. I know it depends, but for normal usage, how many photograps per set of B/C/Y/M cartriges. I have no idea if this would 10 or 100. I am trying to work out the rough ink cost per 6*4 photograph.