What part of the sentence "I have no problem with 3rd-party batteries, but I have a problem with them masquerading the originals." didn't you understand? What part of the word "illegal" don't you understand?

Amazon sells the original battery for €21, compared to €11 for a seller who pretends to sell original batteries, but in bulk. I don't think that it is obvious from the price alone that the battery is fake.

I agree that Nokia's price (€45) is outrageous. This is why we have third party batteries, brandless.