The price increased ! I paid 750e for it.
To be honest, I will not refill the ET8550, 70ml of ink cost 16e I have other things to do than save 5e per bottle and having much worst quality inks.
ATM I am having an internal thought about what I am doing with 2 printers since the ET8550 from the test that I have done is as good as the pro 10 (except pro 10 is a pigment ink and the fact that I don't do B&W). But let's see maybe I will have a good reason to keep it. At least I am very happy with both, I just was expecting more from the Pro 10 on mate papers.
Refiling the pro 10 has some sense if you do high volume prints because the ink in Germany costs 15e + shipping per cartridge.