100% No it isn't ..
( tho I don't know what the situation is in Americky of course)
If I was offered a MP cheap and it worked for me, couldn't care less what it says on it, if it's silly cheap then I'm obviously aware it's very likely not 'genuine' ..as long as I'm not knowingly trying to flog it on subsequently as the real thing there's no foul.
I'd agree with this, and I do not think if one knowingly purchases a counterfeit, aware it is counterfeit, it IS actually a crime, here (especially given the US is now a completely lawless state).
So I would not really be committing any skullduggery ...UNLESS I bought the fake, emblazoned with the brand name it was faking...THEN RESOLD IT, representing it as the ORIGINAL.
But if I knowingly purchased the counterfeit, because I liked how it performed, then after a while SOLD it but identified it as a counterfeit...morally, for me, nothing bad done there.
I DO realize that others have different litmus tests. A customer once buy-traded in a clearly fake, Chinese (?) Selmer, France alto on a horn purchase, I gave him $100 credit towards the purchase for it.
I DID discover, upon trying to re-sell it, that I had made an error PURELY FROM a horn dealer perspective. Although I clearly identified it as a fraud, and even stated "understand: despite the engraving, this is not a Selmer, it is a forgery"...I had my ads pulled down by a few platforms when I somewhat naively though I would have covered my bases by stating that.
Started a thread on that experience, git a lotta opinion but the majority was in agreement - I should not really do that even with the disclaimers I noted. I should have at least obliterated the engraving, or added an engraving which stated "counterfeit of", etc...
Also, and this was another really valid point - if you sell the fake to someone and you know its fake and they know it's fake...what is to stop them from taking that $25 mouthpiece or $150 sax and reselling it as original for $200-300 or $3000 ?
Once it is out of your hands, you have no leverage on that any longer. So, this is where the moral argument comes in: despite your (my) honest attempt to reveal it as fake, you (I) may have unwittingly supported conning someoneelse (or several people) down the line, thus you HAVE actually supported the counterfeit industry.
Moral of story - I am NOT gonna do that ever again.
MY suggestion to others - you gonna sell your fake link or fake Yani or Selmer to ANYONE but a close friend who would not turn it as the original ?....remove or alter out the engraving or printed logo.