The Hp Premium Plus Photo Paper is 0.85 EUR per A4 sheet locally. And the most frequently replaced cartridges for the HP D7360 contain only 5.5-6.0 ml of ink. Moreover, I regularly print with the Best setting (one step down from top quality) and up to now, most of my prints have been rather low-key.
No wonder they come expensive.
But I do not regret switching from lab to home printing. The control I now have over the output (color consistency, finetuning, cropping to format, borders, immediate results) is worth the cost for me - even if it turns out to be twice as high as the lab prints I have never been quite happy with.