I do suppose I went a bit far by using the words malicious intent as if it was premeditated. My apologies for that. I agree that 75 dollars is too high of a price for headphones, but I've honestly seen crazier prices for official items.
The offer the buyer made, however, was made under the presumption that it was authentic. I do not think he grasped that they were 3-dollar knockoffs.
That said, you are right in that the buyer also bears a certain responsibility. However, then we are perhaps more looking into legalities (an actual fraud case) than the moralities, which I am trying to discuss. If one were to make an actual court case out of this, then the attorney could argue caveat emptor... But as I said, that is not what I am trying to discuss.
In my opinion, it should've been made clear that the headphones were 3-dollar headphones specifically before being able to sell it with a clear conscience. The buyer bears as much responsibility to do research as the seller bears responsibility to inform the buyer of anything relevant. Similarly, if one were to offer me 10 000 dollars for a car, I'd tell them everything that's right and wrong with the car so that the buyer knows what they spend their money on.
As an aside... The pharmaceutical industry gets accused of immoralities on a daily basis.
