The costs per page in color are based on a rather high filling rate of 5% per color (5% cyan + 5% magenta + 5% yellow + 5% black) on a sheet of A4.

The costs of black and white are based on a filling rate of 10% black.

Photo costs are based on a 10 x 15 cm print and include the cost of ink and the paper recommended by the manufacturer; for the paper, we used a sheet of A4 cut in four, giving us an A6 format (105 x 148.5 mm; very close to a 10 x 15 cm but a lot cheaper).

In this respect, it's better to be American than European when you need to print, as American prices are much more consistent than in Europe, where there are substantial differences from one manufacturer to another.

That said, whatever side of the Atlantic you live, Canon comes out on top.